Master Lock Magnetic Key Holder, Key Storage Box to Hide Keys Black 207D
4.5Editor score
Durable plastic construction
Sliding cover design
Compact interior space
In this guide
Finding a reliable way to hide spare keys under your vehicle is essential for security and convenience. A good magnetic key box must adhere firmly to metal surfaces while protecting contents from weather and theft.
We evaluated ten top-rated models based on magnet strength, weather resistance, capacity, and ease of access. Our comparison covers diverse designs to suit cars, trucks, and outdoor equipment needs.
Each pick highlights unique strengths like extra magnets or combo locks. Prices and availability change frequently, so check the linked pages for the most current details before purchasing today.
Top 3 Picks for Best Magnetic Key Box for under Car
Magnetic Key Box for Under Car, Hide a Key Outside with Combination Lock Box
4.2Editor score
5 strong magnets included
Resettable 4-digit lock
Waterproof storage bags
Hide a Key Outside with our Grey Magnetic Box, Our Waterproof Air-Tight Magnetic Key Box for Under Car
4.6Editor score
Air-tight seal design
2 strong magnets included
Reliable undercarriage fit
Top 10 Best Magnetic Key Box for under Car in 2026 Compared
The following table provides a side-by-side comparison of all ten products evaluated in this guide, highlighting their key specifications and distinct features for easy reference.
ProductsSpecificationsEditor scorePrice
Best Budget
Magnetic Key Box, Hide A Key Holder, Under Car Magnetic Key Storage
Waterproof magnetic holder
Portable secure case
Super strong magnet
Undercarriage placement
4.6Editor score
Editor's Choice
2 Hide A Key Magnetic Under Car Spare Key Holder So You Never Locked Out of Home Shed RV Boat Truck Office Storage Large ABS Case Key Hider Small Valubles Premium Magnet By ALAZCO
2 premium quality magnets
Tough ABS case
Multi-use storage
Jumbo size fit
4.6Editor score
Best Premium
Large Magnetic Key Box for Under Car, Fits Bulky Key Fobs
Large capacity housing
Four-magnet mounting
Dual retention latches
IPX5 protection
4.3Editor score
Master Lock Magnetic Key Holder, Key Storage Box to Hide Keys Black 207D
Stores 1-2 keys
Sliding cover stop
Steel surface attach
Compact dimensions
4.5Editor score
Magnetic Key Box for Under Car, Hide a Key Outside with Combination Lock Box, Resettable Safe Security Code Lockbox with 5 Strong Magnets, Anti-drop Magnetic Holder Under Car, Truck, Outdoor (1,Black)
5 strong magnets
4-digit password
Ultra-durable material
Includes waterproof bags
4.2Editor score
Magnetic Key Holder Under Car,Weatherproof Magnetic Key Box Under Car,Hide a Key Magnetic Key Box,Hidden Key Holder Magnetic Key Hider Outdoor 【Splash Resistant】
2 Neodymium magnets
60 lbs force
Splash resistant
Removable padding
4.7Editor score
Upgraded Magnetic Key Holder Under Car with Padding
Thick sturdy build
51 lbs force
3 neodymium magnets
Safety buckle design
4.6Editor score
Nite Ize Hideout Magnetic Key Box – Waterproof Key Hider – Magnetic Key Holder & Box – Waterproof Key Storage for Spare Keys – Black, Extra Large
IPX7 waterproof
Strong magnets
Adhesive plate included
Versatile attach
4.6Editor score
Magnetic Key Box with 3 Magnets, Magnet Key Holder for Under Car
3 powerful magnets
Weatherproof design
Rugged ABS plastic
Easy install
4.6Editor score
Hide a Key Outside with our Grey Magnetic Box, Our Waterproof Air-Tight Magnetic Key Box for Under Car Stays Secure with 2 Strong Neodymium Magnets
Air-tight seal
2 strong magnets
Undercarriage fit
Reliable solution
4.6Editor score
1. Magnetic Key Box for Under Car – Best Overall Security
Magnetic Key Box for Under Car, Hide a Key Outside with Combination Lock Box
5 strong magnets
4-digit combo lock
Ultra-durable material
Waterproof bags included
This model stands out as the top pick for security due to its combination lock and robust magnetic system. It offers extra peace of mind for those who worry about unauthorized access to their spare keys.
Pros
- Strong magnetic fixation
- Resettable security code
- Multiple waterproof bags
- Protective padding inside
- Anti-drop design
Cons
- Higher price point
- Requires code management
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The five magnets provide a stronger hold than single-magnet boxes, keeping the unit secure even on bumpy roads. The included waterproof bags add an extra layer of protection against moisture and dust.
While the combination adds security, it also requires you to remember the code. Some users might find the extra step slightly less convenient than a simple slide-open case.
Ideal for fleet managers or homeowners who need maximum security, this box balances safety with practical storage for keys and small valuables like trackers or cards.
Enhanced Magnetic Stability
With five strong magnets, this box grips chassis metal tightly to prevent slippage even during high-speed travel.
Customizable Security
The resettable four-digit lock ensures that only authorized users can access the keys stored inside the compartment.
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2. Master Lock Magnetic Key Holder – Best Budget Option
Master Lock Magnetic Key Holder, Key Storage Box to Hide Keys Black 207D
Stores 1-2 keys
Sliding cover stop
Steel surface attach
Compact dimensions
Master Lock delivers a no-frills solution that works well for basic key hiding needs without breaking the bank. Its design focuses on simplicity and ease of use for everyday situations.
Pros
- Very affordable price
- Reliable brand name
- Simple sliding cover
- Compact size
- Durable plastic
Cons
- Not for cars specifically
- Small internal space
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The sliding cover with a built-in stop ensures the lid doesn't get lost when you need to grab a key quickly. The durable plastic casing protects keys from direct contact with road grime.
It is intended for general steel surfaces and may not have undercarriage-grade magnets. The small size might not fit larger key fobs or multiple items comfortably.
Perfect for rental properties or tool sheds, this box provides trusted storage for a single key. Choose it if you need a simple, low-cost way to secure a spare outside.
Simple Operation
The sliding cover mechanism allows you to access keys quickly without fumbling with locks or complicated opening procedures.
Trusted Brand Quality
Master Lock products are known for durability, ensuring that the box withstands minor weather and physical wear.
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3. Hide a Key Outside with our Grey Magnetic Box – Best Premium Seal
Hide a Key Outside with our Grey Magnetic Box, Our Waterproof Air-Tight Magnetic Key Box for Under Car
Air-tight seal
2 strong magnets
Undercarriage fit
Reliable solution
This premium model features an air-tight design that offers superior protection against water and dust compared to standard plastic boxes. It is ideal for climates with heavy rain or mud.
Pros
- Air-tight waterproof seal
- Strong neodymium magnets
- Grey discreet color
- Undercarriage optimized
- High reliability
Cons
- Higher price
- Fixed magnet count
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The neodymium magnets provide a secure attachment to your chassis, minimizing the risk of loss while driving. The grey color helps the box blend in with vehicle undercarriages.
The price reflects its higher build quality and sealing technology, which might be more than some casual users need. It is a specialized tool for rigorous outdoor conditions.
Choose this for off-road vehicles or boats where moisture protection is critical. The reliable design ensures your keys stay dry and accessible whenever an emergency occurs.
Superior Water Protection
The air-tight seal prevents water and moisture from entering the box, ensuring keys remain dry even in wet conditions.
Secure Magnetic Fit
Powerful neodymium magnets keep the box firmly attached to the vehicle undercarriage during normal driving maneuvers.
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4. Magnetic Key Box, Hide A Key Holder – Best Standard Option
Magnetic Key Box, Hide A Key Holder, Under Car Magnetic Key Storage
Waterproof magnetic holder
Portable secure case
Super strong magnet
Undercarriage placement
This option offers a balanced combination of waterproofing and magnet strength at a standard price point. It serves as a reliable choice for typical vehicle use.
Pros
- Waterproof design
- Easy portability
- Secure strong magnet
- Compact dimensions
- Travel friendly
Cons
- Basic feature set
- Small interior space
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The dimensions are small enough to be discreet yet large enough for a standard key set. The strong magnet ensures it stays put during everyday driving on paved roads.
It lacks extra features like combination locks or zip-tie holes, which might limit versatility. However, it fulfills the basic need for a spare key holder effectively.
Buy this if you need a straightforward, waterproof solution for a car trunk or undercarriage. It is a solid choice for regular travelers and commuters.
Compact Portability
The small dimensions make it easy to hide discreetly under the car without interfering with vehicle components.
Secure Storage
Strong magnets provide a reliable hold on the vehicle frame to keep keys safe from falling off.
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5. ALAZCO Hide A Key Magnetic Under Car Spare Key Holder – Best Large Case
2 Hide A Key Magnetic Under Car Spare Key Holder So You Never Locked Out of Home Shed RV Boat Truck Office Storage Large ABS Case Key Hider Small Valubles Premium Magnet By ALAZCO
2 premium quality magnets
Tough ABS case
Multi-use storage
Jumbo size fit
This model is designed for those who need extra space for keys and small valuables. The large ABS case offers robust protection against impacts and rough handling.
Pros
- Large ABS case
- Premium magnets included
- Multi-use for valuables
- Pre-measured sizing
- Tough weather resistance
Cons
- Size might be bulky
- Slide open mechanism
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The slide-open mechanism is straightforward but ensures the case stays securely closed when not in use. The premium magnets are strong enough to hold the box during moderate travel.
The jumbo size might make it harder to hide under low-clearance cars. It is better suited for trucks or RVs where there is more undercarriage space.
Ideal for families or businesses needing to store cash or trackers alongside keys. This case provides versatility and durability for various storage needs.
Large Storage Capacity
The extra size allows you to store more than just keys, including small valuables or emergency items.
Tough Weather Resistance
The ABS case is designed to withstand outdoor weather conditions without cracking or degrading over time.
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6. Large Magnetic Key Box for Under Car – Best for Fobs
Large Magnetic Key Box for Under Car, Fits Bulky Key Fobs
Large capacity housing
Four-magnet mounting
Dual retention latches
IPX5 protection
This box is specifically designed to accommodate modern smart key fobs that do not fit in standard small containers. The large housing ensures everything stays organized and secure.
Pros
- Fits bulky fobs
- Four-magnet mounting
- IPX5 weather protection
- Optional zip-tie holes
- Secure latches
Cons
- Heavier than others
- Larger profile
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The four-magnet system distributes force evenly across the metal surface, providing a very stable mount. IPX5 protection handles rain and road spray effectively.
The size may be a disadvantage for tight undercarriage spots. It requires a flat ferrous surface for best results, which might not be available on all cars.
Perfect for owners of newer vehicles with large remote starters or fobs. Use it where you need to ensure bulky items fit comfortably without damaging electronics.
Smart Key Compatibility
The large capacity housing ensures that bulky key fobs fit without forcing or damaging the internal components.
Dual Retention Security
Four latches keep the box closed firmly, and zip-tie holes offer extra security if needed.
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7. Magnetic Key Holder Under Car – Best Splash Resistant
Magnetic Key Holder Under Car,Weatherproof Magnetic Key Box Under Car,Hide a Key Magnetic Key Box,Hidden Key Holder Magnetic Key Hider Outdoor 【Splash Resistant】
2 Neodymium magnets
60 lbs force
Splash resistant
Removable padding
This model delivers a strong magnetic hold of 60 lbs which is exceptional for vehicle use. It is highly rated for staying secure on uneven terrain or highways.
Pros
- High pull force
- Removable padding inside
- Dark color stealth
- Two zip-tie holes
- Hard plastic build
Cons
- Splash resistant not waterproof
- Padding may need removal
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The dark color helps it stay hidden visually. Removable padding lets you customize storage space depending on whether you need noise reduction or volume.
It is splash resistant but not waterproof for prolonged submersion. You should bag keys if you expect deep puddles or heavy rain exposure.
Great for daily drivers needing reliable key storage that stays in place. The zip-tie option gives flexibility for alternative mounting if steel is unavailable.
Strong Hold Force
The 60-pound separation force ensures the box stays attached even during high-speed driving or bumpy roads.
Versatile Mounting Options
Two holes allow for zip-tie attachment, offering an extra layer of security beyond the magnetic hold.
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8. Upgraded Magnetic Key Holder Under Car with Padding – Best for Protection
Upgraded Magnetic Key Holder Under Car with Padding
Thick sturdy build
51 lbs force
3 neodymium magnets
Safety buckle design
This upgraded model focuses on robust build quality and item protection. It includes internal cushioning to prevent keys from rattling against the plastic walls.
Pros
- Thick sturdy material
- Safety buckle design
- Internal cushioning
- Weatherproof tested
- 51 lbs hold
Cons
- Heavier construction
- Padding removes for space
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The safety buckles ensure the lid does not open accidentally during travel. It has been tested against snow and rain to confirm weatherproof claims.
The thickness adds durability but also bulk, which might make it harder to hide. The weight ensures it stays fixed securely without wobbling.
Choose this if you want extra protection for keys and valuables. The safety buckles provide confidence that the box will not open unexpectedly.
Item Protection
Internal soft cushioning protects keys from abrasion and prevents rattling noise during vehicle movement.
Safety Latching
Upgraded buckles are designed to endure repeated bending without detachment, keeping the box securely closed.
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9. Nite Ize Hideout Magnetic Key Box – Best Waterproof Standard
Nite Ize Hideout Magnetic Key Box – Waterproof Key Hider – Magnetic Key Holder & Box – Waterproof Key Storage for Spare Keys – Black, Extra Large
IPX7 waterproof
Strong magnets
Adhesive plate included
Versatile attach
Nite Ize offers a trusted product with an IPX7 waterproof rating ensuring contents stay dry even in deep splashes. The brand reputation adds reliability to the purchase.
Pros
- IPX7 waterproof rating
- Includes adhesive plate
- Strong neodymium magnets
- Versatile attachments
- Worry Free Guarantee
Cons
- Price above average
- Adhesive plate required
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The included adhesive plate allows mounting on non-metal surfaces like plastic bumpers. Strong magnets secure it to steel parts when needed.
It might be more expensive than generic options. The reliance on an adhesive plate for some mounts can be a minor inconvenience if you prefer direct metal contact.
Ideal for anyone prioritizing waterproof standards and brand support. Use it for boats or cars exposed to frequent water or moisture risks.
Waterproof Standard
The IPX7 rating ensures the box is fully waterproof and safe from water immersion for short periods.
Versatile Mounting
An included adhesive plate allows attachment to wood or plastic surfaces beyond standard metal ones.
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10. Magnetic Key Box with 3 Magnets – Best Balanced Value
Magnetic Key Box with 3 Magnets, Magnet Key Holder for Under Car
3 powerful magnets
Weatherproof design
Rugged ABS plastic
Easy install
This box combines multiple magnets with a rugged ABS build to offer good value. The triple magnet setup ensures it stays attached securely during daily drives.
Pros
- Triple magnet strength
- Rugged ABS build
- Weatherproof design
- Low-profile shape
- No tools needed
Cons
- Standard lid closure
- Basic aesthetic
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It is designed specifically for under-car placement with a low-profile look that avoids interference. Weatherproofing protects keys from rain and mud effectively.
The design is functional without extra frills which keeps costs down. It may not have the extra features of higher-end models.
Best for general vehicle owners needing a reliable and affordable option. It provides peace of mind with its strong hold and durable build.
Triple Magnet Hold
Three magnets provide strong attachment to ferrous surfaces ensuring keys remain secure during travel.
Easy Installation
No tools are required to place the box under the vehicle making setup quick and straightforward.
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Buying Guide – How to Choose the Best Magnetic Key Box for under Car
Choosing the right magnetic key box involves considering magnet strength, weather resistance, capacity, and security features to ensure reliable spare key storage.
Magnet Strength and Count
Stronger magnets ensure the box stays attached during high-speed driving or on rough roads. Look for multiple neodymium magnets or a high pull force rating like 60 lbs to prevent loss.
Prioritize boxes with more magnets for better stability and security against falling off your vehicle.
Waterproof and Weather Resistance
Your keys need protection from rain, snow, and road spray to remain functional. Look for waterproof ratings like IPX5 or IPX7 or air-tight seals to keep moisture out.
Choose a model that can withstand your local climate conditions to avoid corrosion or water damage.
Capacity and Size
Ensure the internal dimensions can fit your specific keys including large remote fobs. A box that is too small may not hold your spare or other valuables you want to stash.
Measure your keys and consider extra space for cards or trackers before selecting a size.
Security Features
Some boxes include combination locks or zip-tie holes for added security beyond just magnets. This can prevent unauthorized access if someone finds the hidden spot.
If theft is a concern, choose a box with a lock or secondary retention method.
Mounting Options
Most boxes mount on steel surfaces but some include adhesive plates for non-metal areas. Check if your vehicle has the required flat metal surface for installation.
Verify the mounting method matches your vehicle to ensure a secure fit.
Durability and Material
Look for ABS plastic or sturdy materials that resist cracking under extreme temperatures or road debris. A durable casing protects both the keys and the box itself.
Invest in a box with quality materials that will not degrade quickly over time.
Ease of Access
Consider how quickly you can open the box in an emergency. Simple latches or sliding covers are often faster than fumbling with codes when stressed.
Balance security features with convenience to ensure you can access your key when needed.
How to Use and Care for Your Magnetic Key Box for under Car
To install, clean the metal surface under your vehicle thoroughly to ensure strong magnetic contact. Place your spare keys inside and close the lid securely before positioning it under the chassis.
Regularly check the magnets and casing for any signs of rust or wear especially after exposure to harsh weather. Dry the box after heavy rain to maintain its waterproof integrity.
If using zip-tie options ensure they are tightened properly to avoid accidental detachment. Rotate the hiding spot occasionally if possible to avoid predictable placement.
Frequently Asked Questions
Are magnetic key boxes safe to use under cars?
Yes when you choose a box with strong neodymium magnets designed for vehicles. Proper installation on clean flat metal ensures the box stays secure during driving.
How waterproof are these boxes?
Many models offer IPX5 or IPX7 ratings which protect against rain and splashes. For deep submersion you should place keys inside additional sealed bags.
Can I use these on trucks or RVs?
Most boxes work on any ferrous steel surface including trucks and RVs. Ensure the magnet strength is sufficient for the vehicle weight and road conditions.
Will the magnets affect my car electronics?
The magnets are generally safe as they are placed away from sensitive electronics. Keep the box away from wiring harnesses and sensors for optimal safety.
How do I choose the right size?
Measure your key fob and any extra items you want to store. Select a box with internal dimensions that comfortably fit your items without forcing them.
Do these boxes rust over time?
Most are made of durable plastic which resists rust but the magnets themselves may corrode in extreme wet conditions. Regular inspection helps prolong their lifespan.
Final Thoughts on Choosing the Best Magnetic Key Box for under Car
The top picks include options with combo locks strong magnets and waterproof seals to suit different needs and budgets. Each model offers a secure way to store spare keys out of sight.
Focus on magnet strength and weather resistance when making your decision to ensure reliability during emergencies. Consider extra features like zip-tie holes or large capacity if needed.
Prices and availability may change so always check the latest details before purchasing. With the right box you can avoid lockouts and keep your keys safe.