The 10 Best Manual Lawn Aerators For Backyard Turf of 2026

This RIFPOD manual lawn aerator is a game-changer for homeowners tackling compacted soil in small to medium backyards. With 15 sharp iron spikes and a clever double spring system, it punches neat holes deep into the ground, letting air, water, and nutrients reach grass roots for lusher growth. It's perfect for beginner gardeners or busy folks who want pro-level results without renting heavy machines.

In real-world use, the patent-pending springs automatically eject dirt and leaves after each push, so you stay in the flow without pausing to clean. The wide foot plate helps drive spikes 1.74 inches deep evenly, even in moderately tough yards, while adjustable height keeps your back happy as you work across uneven terrain. Reviewers love how it revives bare spots and dog-trampled areas, making seed germination easier by keeping birds at bay.

Built from thickened iron with rust-resistant spraying and solid welding, this yard aerator holds up through seasons of damp springs and hot summers. At just over 6 pounds, it's maneuverable yet feels substantial, with no wobbling during operation. Assembly is a breeze with two screws and a wrench included.

Limitations include the need for some foot pressure on dense clay soil and its manual nature, which suits spot work over vast lawns. A quick tape wrap can quiet any handle noise. Overall, if you're serious about healthier turf without backache, this reliable tool earns a spot in your garden shed.

To use: Adjust height to chest level for comfort. Water lawn lightly beforehand for easier penetration. Step firmly on the foot plate, rock gently, then lift; springs auto-clear debris. Work in a grid pattern, overlapping holes 4-6 inches apart. Best in spring or fall on cool-season grass.

• Aerate when soil is moist but not soggy
• Pass over high-traffic areas twice
• Follow with topdressing or seeding for best results

Maintenance: Wipe clean after use. Store dry to prevent rust. Check springs and spikes seasonally; tighten bolts as needed. Oil moving parts lightly for smooth action.

Aeration relieves soil compaction from foot traffic, pets, or mowers, boosting lawn health. Do it annually for clay soils or high-use yards.

• Timing: Early spring or fall, before heavy rain
• Signs you need it: Water puddles, thin grass, weed invasion
• Aftercare: Leave plugs to break down naturally; fertilize lightly
• Combine with dethatching for dramatic improvement

For small yards under 5,000 sq ft, manual tools like this shine over powered rentals.

Ideal for: Small backyards (up to 1/4 acre), flower bed edges, or spot repairs. Efficient for 30-60 minute sessions without fatigue.

• Small yard (<2,000 sq ft): Perfect standalone tool
• Medium yard (2,000-5,000 sq ft): Great for targeted aeration
• Large yard (>5,000 sq ft): Use for problem areas; pair with tow-behind for full coverage

Its portability beats bulky machines for urban or suburban gardeners.

The Walensee manual lawn aerator is a sturdy spike tool designed for homeowners who want to breathe new life into compacted lawns without renting expensive machines. With 15 sharp 2.8-inch iron spikes, it punches holes efficiently to break up thatch and improve soil drainage. It's perfect for beginner to experienced gardeners maintaining small to medium yards, patios, or garden edges in suburban settings.

Key Features and Real-World Performance

In everyday gardening, this aerator shines by letting air, water, and fertilizers reach grass roots deeply. Push down with the foot bar and pull back using the cushioned T-handle to create uniform holes across your lawn. Users appreciate how it preps soil for seeding, resulting in lusher growth and fewer bare spots after a single session.

Build Quality and Durability

Built from heavy-duty, powder-coated iron, it resists rust and holds up in wet or sandy conditions. At 34.6 inches tall and 4.53 pounds, it's lightweight yet stable, minimizing strain during use. The design avoids the instability of spike shoes, offering reliable performance season after year.

Limitations and Practical Tips

While effective, it demands some muscle for rocky or very hard soils, so water your lawn first for best results. Not suited for acres of turf, but ideal for targeted yard revival. Disassembles easily for storage in sheds or garages.

Final Verdict

For affordable, hands-on lawn care that delivers real results, the Walensee aerator earns high marks. Grab it if your yard needs a health boost, and pair with overseeding for a vibrant outdoor space you'll enjoy all summer.

Step-by-Step Usage Guide

1. Prep your lawn: Mow short and water if soil is dry for easier spike penetration.
2. Assemble if needed: Attach T-handle, pole, and foot pedal using bolts and wrenches.
3. Aerate: Position spikes over grass, step on foot bar, rock back and forth, then lift and move 4-6 inches ahead.
4. Overlap passes for even coverage, focusing on high-traffic areas.
5. Aftercare: Leave plugs on lawn to break down naturally, then fertilize or seed.

Best Times to Aerate

• Spring or fall when grass is actively growing.
• Avoid summer heat or winter freezes.
• Aerate cool-season grasses like fescue yearly; warm-season like Bermuda every 1-2 years.

Aerate every 6-12 months for healthier roots and reduced watering needs.

Cleaning and Storage

• Wipe spikes clean after each use to remove soil and debris.
• Rinse with hose and dry to prevent rust; apply light oil if needed.
• Disassemble for compact storage in your garden shed.
• Inspect bolts and spikes annually for wear; tighten as necessary.

Pairing with Lawn Routines

Combine aeration with dethatching rakes, compost topdressing, and balanced fertilizers for optimal yard health. For New York homeowners, aerate in early spring to combat clay compaction from winter snow, leading to drought-resistant turf.

Pro Tip: Test soil pH post-aeration to fine-tune your lawn's nutrition.

Ideal Yard Sizes

• Best for: Up to 5,000 sq ft; quick sessions under an hour.
• Large yards: Use in sections or consider powered options.

Soil Type Compatibility

• Clay: Excellent for breaking compaction; moisten first.
• Sand/Loam: Effortless penetration and drainage boost.
• Rocky: May skip stones; focus on softer areas.

This tool transforms everyday lawns into thriving spaces, especially for urban gardeners fighting poor drainage.

As a fellow gardener who's battled compacted clay soil in my own backyard, I appreciate a reliable manual lawn aerator like the LawnVigor Core Aerator. This semi-assembled tool features three heat-treated hollow tines mounted on a sturdy foot plate, perfect for homeowners with small to medium lawns who want to skip the rental machine hassle. It suits beginner to experienced gardeners focused on practical lawn revival without breaking the bank.

Key Features and Real-World Performance

In action, the sharp tines punch through moist soil effortlessly, pulling out neat plugs up to 3 inches deep. This core aeration breaks up compaction, allowing roots to breathe and water to soak in better, leading to lusher grass growth. The non-clogging design keeps things moving smoothly, even in tougher yard spots like high-traffic areas near patios.

Build Quality and Durability

Constructed from robust metal with an ergonomic, non-slip handle, it feels solid yet lightweight for easy storage in a garden shed. The tines are replaceable for long-term use, holding up well against rocky soil over multiple seasons of lawn care.

Limitations and Practical Tips

• Not suited for very large properties where powered aerators shine.
• Always water soil first to avoid strain and ensure penetration.

Verdict: A smart pick for targeted aeration in home lawns. Use it in spring or fall for noticeable improvements in turf health and reduced watering needs.

Step-by-Step Aeration Guide

1. Prep the lawn: Mow short and water soil thoroughly the day before to soften it.
2. Position and pump: Stand on the foot plate, push down firmly with your body weight, then pull straight up. Avoid twisting to prevent damage.
3. Work in patterns: Space holes 4-6 inches apart, covering the yard in rows for even coverage.
4. Finish up: Leave plugs on the lawn to break down naturally, then fertilize and water deeply.

Aerate cool-season grasses like fescue in fall, warm-season types like Bermuda in late spring. Aim for 20-40 passes per square yard for optimal results.

Tool Care

• Clean tines after each use with a brush to remove soil buildup.
• Store in a dry place to prevent rust; apply light oil to metal parts seasonally.
• Inspect tines for wear and replace as needed for consistent performance.

Lawn Aeration Best Practices

Aerate annually if your soil is compacted from foot traffic or heavy clay. Pair with overseeding for patchy lawns and topdressing with compost to fill holes. This combo transforms tired turf into a vibrant backyard oasis.

Timing by Grass Type

• Cool-season grasses (Kentucky bluegrass, ryegrass): Early fall or spring when actively growing.
• Warm-season grasses (Zoysia, St. Augustine): Late spring to early summer.
• Avoid summer heat or winter dormancy to prevent stress.

Signs you need it: Thin patches, puddling water, or spongy feel underfoot. For New York-area lawns, fall aeration preps for winter and promotes strong spring recovery.

This GAINO manual lawn aerator is a foot-powered tool perfect for U.S. homeowners with compact yards or patchy lawns suffering from soil compaction. It's ideal for beginner gardeners or busy folks who want pro-level aeration results without renting expensive machines.

The standout features shine in real-world use: 15 hollow spikes drive 2.76 inches deep to pull out soil cores, while the dual-spring system shakes off debris instantly. Users report it works best after light watering or rain, making aeration smoother and faster than older two-prong tools. The adjustable T-handle provides leverage and comfort, letting you maintain good posture over long sessions.

Built from thickened iron with arc welding and a sprayed rust-proof finish, it feels solid and holds up to tough outdoor conditions far better than plastic alternatives. Reviewers praise its sturdiness, noting it doesn't bend or wobble during heavy pushing.

Limitations include the physical effort needed for rocky or bone-dry soil, and it's not practical for acres of lawn. Some mention the springs need a few uses to work smoothly.

Overall, this aerator delivers reliable performance for healthier lawns. Grab it if you have a modest yard and want to boost grass vitality through better soil health.

Prep your lawn: Mow short and water lightly the day before to soften soil, especially if compacted.

• Adjust handle height to 32-35 inches using included wrench for your comfort.
• Position spikes over target area, step firmly on top plate with foot to drive into ground.
• Lift straight up; springs eject cores automatically.
• Overlap passes by 4-6 inches for even coverage.
• Aerate in spring or fall when grass is growing actively.

Pro tip: Work in sections to avoid fatigue, and follow with fertilizer or overseeding for lush results.

Aeration relieves soil compaction from foot traffic, pets, or clay-heavy dirt, promoting stronger roots and drought resistance.

• Do it annually for high-traffic yards or every 2-3 years for low-use lawns.
• Combine with topdressing sand or compost to fill holes and improve drainage.
• Focus on thin, brown, or water-repelling spots first.
• Avoid aerating during extreme heat or drought to prevent grass stress.

Expect visible improvements in water absorption and green-up within weeks.

Keep your aerator ready for seasons with simple care.

• Clean spikes after each use by tapping or hosing off dirt.
• Check springs and welds for wear; oil lightly if sticky.
• Store detached in a dry shed to prevent rust.
• Tighten screws periodically for stability.

This all-steel build lasts years with basic upkeep, outpacing flimsy competitors.

The Bluesea Lawn Aerator is a sturdy manual tool designed for homeowners tackling compacted soil in their backyards. With 16 sharp 3.5-inch spikes in a 4x4 grid, it punches holes to relieve soil density, perfect for beginner to experienced gardeners maintaining cool-season or warm-season grasses on lots up to half an acre.

In real-world use, the ergonomic T-handle and foot-bar make thrusting spikes into moist soil straightforward, while the double-layer spring mechanism shakes off dirt automatically after each push. This keeps the tool clean and efficient, turning a tedious task into a quick lawn booster that improves water absorption and root health right away.

Build quality shines with reinforced 2mm steel plates welded for strength and coated against rust, holding up well to damp grass and storage in sheds. It's heavier than plastic models but feels solid, promising years of service without bending or dulling.

Limitations include the need for soil prep, like watering dry ground a day ahead, and it's not suited for rocky soil or huge lawns where powered aerators excel. Overall, this is a smart pick for practical yard care; aerate in spring or fall, then top-dress for lush results that make your lawn the neighborhood envy.

Prep your lawn: Mow short, water dry soil 1-2 days prior for moist but not muddy conditions.

• Assemble by attaching the steel tube and tightening screws; spikes are pre-installed.
• Stand on the foot-bar, push down with body weight, then pull up to let springs eject dirt.
• Aerate in a grid pattern, overlapping passes for even coverage; work when soil is firm enough to hold holes.

Care tips: Knock off stuck soil, wipe clean, apply oil to metal parts, and store dry to avoid rust. Sharpen spikes if needed with a file for peak performance next season.

Aerate cool-season grasses like fescue in early spring or fall; warm-season types like Bermuda in late spring. Do it every 1-2 years, or annually for high-traffic yards.

• After aerating, top-dress with sand or compost to fill holes and amend soil.
• Fertilize lightly and water deeply to speed grass recovery and root growth.
• Avoid aerating during drought or extreme heat to prevent lawn stress.

Pair with overseeding for bare spots to achieve a thicker, greener turf that thrives through summer.

Best for small to medium yards under 5,000 sq ft where manual effort stays manageable in 1-2 hours.

• Tiny urban lots (under 1,000 sq ft): Quick job, ideal for apartments with patches of grass.
• Suburban backyards (1,000-10,000 sq ft): Efficient with overlapping passes; rent power units for bigger areas.
• Not recommended for over 1/4 acre without breaks to avoid fatigue.

Combines well with core aerators for deeper renovation on heavily compacted play areas.

As a fellow gardener, I appreciate tools that make lawn maintenance straightforward without fancy machines. The Leweio Manual Lawn Aerator is a spike tool with four heat-treated steel tines that punch holes in compacted soil, ideal for U.S. homeowners with small to medium yards who want to revive tired grass or prep for seeding.

In real-world use, the 2.2-inch tines slice through clay or thatch effortlessly, far better than basic spikes, letting water and fertilizer reach roots for lusher growth. The ergonomic handle keeps you upright, and the foot bar multiplies your force for deep aeration without tiring your back, perfect for spot-treating high-traffic areas near patios or play zones.

Built from powder-coated iron with reinforced welding, it withstands outdoor conditions and rust, holding up under full weight season after season. Users love how the non-clogging blades shed dirt easily, saving time on cleanup.

It's not for massive lawns needing powered gear, and the sharp tines demand respect, but for everyday yard aeration, it's a reliable winner that boosts drainage and lawn health.

Grab this if your soil feels packed; pair it with overseeding for a greener backyard that thrives all season.

Start by mowing your lawn short and lightly watering the soil a day before to soften it. Position the tool over compacted spots, step firmly on the foot bar, and rock gently to drive tines in.

• Aerate in spring or fall when grass is actively growing.
• Space holes 4-6 inches apart in a grid pattern for even coverage.
• Work in sections to avoid fatigue, using your body weight for leverage.
• After aerating, top-dress with compost and water deeply.

Ideal for lawns under 5,000 sq ft; follow up with fertilizer for quick green-up.

Keep your aerator performing like new with simple care. Rinse soil off tines after each use and dry thoroughly to prevent rust.

• Apply a light oil coat on metal parts seasonally.
• Store upright in a dry shed; use blade covers if provided.
• Inspect welds and tines yearly for wear.
• Avoid sandy soils without rinsing to minimize abrasion.

This routine ensures years of reliable yard aeration.

Aerate when soil compacts from foot traffic, pets, or drought. Signs include puddling water, thin grass, or weed invasion.

• Spring: Before fertilizing to boost root growth.
• Fall: Prep for winter dormancy and next season.
• Avoid summer heat or frozen ground.

Do it once or twice yearly for thriving turf in your backyard.

The Onadak Manual Lawn Aerator is a straightforward, foot-powered tool designed to punch 15 sharp 3-inch spikes into your lawn soil, promoting better root health. It's perfect for homeowners with small to medium yards who want to revive compacted turf without renting expensive machines or buying spike shoes that loosen dirt.

In real-world use, the spring-loaded mechanism makes it easy to drive spikes deep, even into clay-heavy soil after a good watering. The double-layer spikes minimize dirt clogs, keeping the process clean and efficient. Adjustable height from three positions ensures a comfortable stance, whether you're tall or short, reducing fatigue during backyard sessions.

Built from solid iron with a baked enamel finish, this aerator stands up to moisture and rough handling in gardens or lawns. At just 5.5 pounds and 38 inches tall, it's portable and stores easily. The wide footplate supports full body weight for maximum penetration without slipping.

Limitations include its manual nature, best for yards under half an acre, and the need to water dry soil first. Overall, it's a smart pick for practical lawn aeration that delivers noticeable greening and thicker growth. Grab it if you're prepping for seed or just maintaining a healthy yard.

Prep your lawn: Mow short and water thoroughly the day before to soften soil.

• Assemble if needed, ensuring tube connections are secure per instructions.
• Adjust handle height to elbow level for comfort.
• Push down with foot on the plate, let spring assist pull up.
• Overlap passes by 6 inches for even coverage.
• Aerate in spring or fall when grass is growing actively.

Avoid using on wet, muddy ground to prevent clumping.

Aerate annually for compacted lawns or after heavy foot traffic. Signs you need it: thin patches, water pooling, or spongy feel.

• Combine with overseeding and fertilizer for lush results.
• Best for cool-season grasses like fescue or Kentucky bluegrass.
• For warm-season lawns, aerate in late spring.
• Top-dress with compost post-aeration to fill holes naturally.

Regular aeration prevents thatch buildup and boosts drought resistance.

Ideal for yards up to 5,000 sq ft where manual effort stays manageable.

• Small yards (<2,000 sq ft): Quick 30-minute job, perfect for beginners.
• Medium yards (2,000-5,000 sq ft): 1-2 hours; break into sections.
• Large yards (>5,000 sq ft): Consider powered aerators for efficiency.

Great for urban backyards or garden edges needing targeted aeration.

This DomiHapi 2-in-1 manual lawn aerator is a compact, steel-built tool perfect for U.S. homeowners with small to medium yards who want to improve lawn health without renting expensive machines. With 15 sharp spikes and a switchable single or double-layer setup, it punches holes in compacted soil to let air, water, and fertilizer reach grassroots, leading to greener, thicker turf.

In real-world use, the adjustable T-handle rises to a comfortable height, so you can aerate standing straight, saving your back and knees during passes over the yard. Users love how the reinforced connections hold up under pressure, unlike cheaper plastic or weak-metal alternatives that bend or snap. It shines on high-traffic spots, garden edges, and thinning areas, making your outdoor space look revitalized after one session.

Build quality stands out with heavy-duty steel that's weather-resistant for outdoor storage, and the padded grip keeps hands comfy even on longer jobs. While it's lightweight for easy maneuvering, it demands some muscle on bigger lawns or very hard ground, so pair it with seeding or topdressing for best results.

Overall, this is a smart pick for beginner and experienced gardeners alike. Grab it if you want straightforward, effective aeration that delivers noticeable lawn improvements and fits right into your seasonal backyard routine.

To get started, assemble by attaching the spike head to the handle using the provided hardware, following the simple instructions. Adjust the T-handle to your height for upright use. For light aeration, use single-layer spikes; switch to double for compacted soil by adding the extra plate.

• Water your lawn lightly before aerating to soften soil.
• Push down firmly with foot pressure while walking in a grid pattern.
• Clean spikes after each use by tapping or hosing off dirt.
• Store detached parts in a dry spot to prevent rust.

Sharpen spikes occasionally with a file if they dull over time, and oil joints lightly for smooth adjustments.

Aerate cool-season grasses like fescue or bluegrass in early spring or fall, and warm-season types like Bermuda in late spring. Focus on problem areas first: yellow patches, puddles after rain, or bare spots from foot traffic.

• Combine with overseeding for thicker lawns.
• Follow up with fertilizer to boost root growth.
• Avoid aerating during drought or extreme heat.
• Aerate every 1-2 years for healthy soil structure.

This tool pairs great with dethatching rakes for complete lawn revival.

Best for yards under 5,000 sq ft where manual effort stays manageable. For larger spaces, use in sections or consider powered options.

• Small yards (under 2,000 sq ft): Quick 30-minute job, ideal for beginners.
• Medium yards (2,000-5,000 sq ft): 1-2 hours with breaks; double spikes speed it up.
• Large yards: Supplement with rentals for efficiency.

Perfect for urban backyards, suburban lawns, or garden beds needing soil loosening.

This KIMPOK manual lawn aerator is a straightforward hand tool designed for homeowners tackling compacted soil in lawns, gardens, and backyards. With 16 sharp 3.42-inch steel spikes, it's perfect for small to medium yards where you want to improve grass health without renting bulky machines. Beginners and experienced gardeners alike appreciate its focus on everyday lawn care tasks like prepping for overseeding or loosening hard patches.

In real-world use, the 4-spring ejector system shines by automatically clearing debris from spikes, letting you keep aerating without constant stops to clean. The adjustable T-handle, with three height settings from 37.8 to 39.4 inches, promotes ergonomic comfort, protecting your back during longer sessions. Foot pressure on the welded plate drives spikes deep, and the spring lock screws allow depth control for safe turf aeration on various soil types.

Build quality features a heavy-duty iron frame with powder-coated rust resistance, standing up to outdoor demands. At 6.27 pounds, it's manageable yet solid. Some users note assembly can be tricky without printed instructions, but a quick video helps align parts properly.

Limitations include it not being ideal for very large lawns due to manual effort. Overall, it's a reliable choice for targeted aeration that leads to lusher grass and better yard vitality. Grab this if your backyard needs a simple soil boost.

Assembly Tips: Match pieces using product images or videos. Secure handle segments with provided bolts, adjusting height as needed. Tighten spring lock screws for uniform spike exposure.

• Water lawn lightly 30 minutes before use for softer soil.
• Start at a slight angle, step firmly on footplate, then rock upright to pull out.
• Aerate in a grid pattern, overlapping passes for even coverage.

Maintenance: Hose off dirt after use. Store in a dry shed. Check spikes and springs seasonally for wear; apply touch-up paint if needed to prevent rust.

Aerate cool-season grasses in spring or fall, warm-season in late spring or summer. Aim for every 1-2 years or when soil feels hard.

• Combine with overseeding and fertilizer for thicker lawns.
• Focus on high-traffic areas like paths or under trees.
• Follow with topdressing sand or compost to fill holes and improve soil.
• Avoid aerating during drought or extreme heat to prevent stress.

Regular aeration promotes deeper roots, reducing weeds and disease in your backyard oasis.

Ideal for yards under 5,000 sq ft where manual effort stays manageable.

• Small yards (under 2,500 sq ft): Quick 30-60 minute sessions revive turf easily.
• <medium yards (2,500-5,000 sq ft): Split into sections over a weekend.
• Larger properties: Use for spot treatment, pair with tow-behind for efficiency.

Suits urban homeowners, seniors, or anyone avoiding powered equipment noise and cost.

This 2-in-1 manual lawn aerator from Worcest is a game-changer for homeowners battling compacted soil in their backyards. With interchangeable hollow core tines for deep plug removal and solid spike tines for quick loosening, it suits beginner to experienced gardeners maintaining small to medium lawns, especially those with heavy clay like in many U.S. regions.

In real-world use, the core tines pull plugs up to 3.5 inches deep, creating channels for better drainage and root growth, while spikes prep soil for overseeding. The clog-free design with side slots lets soil eject sideways, keeping work smooth even in tough spots near fences or edges. Users note it transforms patchy yards into lush green spaces without the hassle of gas rentals.

Built from thick alloy steel, it resists bending under pressure, outperforming flimsy stainless models in compacted clay. The ergonomic T-handle with cushioned grips and wide foot bar makes stepping easy and back-friendly, ideal for spring or fall lawn care sessions.

Limitations include the physical effort needed for bigger areas, so pair it with a mower for full routines. It's not powered, but that's the trade-off for a lightweight, storable tool.

Overall, this lawn aeration tool earns top marks for durability and versatility. Grab it if your grass struggles with compaction; it's a practical step toward thriving outdoor living.

To aerate, mow your lawn short first and water lightly for moist soil. Position the tool, step firmly on the foot bar, then rock and pull to remove plugs or loosen with spikes. Space holes 4-6 inches apart in a grid pattern for even coverage.

• Swap tines: Unscrew and replace hollow cores or solid spikes as needed for your soil.
• Clean after use: Tap out plugs, rinse tines, and dry to prevent rust.
• Store upright in a shed; oil joints yearly for smooth action.
• Sharpen tine tips with a file if they dull over time.

Follow these steps for seasons of reliable performance in your backyard lawn care.

Aerate to boost lawn health by fighting compaction from foot traffic, mowers, or clay soil. Do it in spring for growth or fall for overseeding cool-season grasses.

• Core aerate heavy clay once or twice yearly for deep relief.
• Spike aerate moderate soil annually before fertilizing.
• Leave plugs on the lawn to break down naturally and enrich soil.
• Top-dress with compost after for best results.

Combine with regular mowing and watering for a vibrant, low-maintenance yard.

This manual aerator shines on small to medium yards under 5,000 sq ft, where you can finish in an afternoon without fatigue.

• Ideal for: Urban backyards, suburban lawns with clay issues.
• Less suited for: Acreage; consider rentals for 10,000+ sq ft.
• Breaks into 15-30 min sessions for larger areas.

Matches everyday U.S. homeowner needs for targeted lawn improvement.