Master Lock Magnetic Key Holder, Key Storage Box to Hide Keys Black 207D
4.5Editor score
Durable plastic construction
Sliding cover with stop
Fits 1-2 keys
In this guide
Finding a reliable place to store spare keys is essential for vehicle owners who want to avoid lockouts. A magnetic key box for under car offers a discreet solution that keeps keys safe while remaining easily accessible when needed by trusted individuals.
We evaluated ten top-rated models based on magnetic strength, weather resistance, and build quality. Each product was analyzed for its ability to secure keys against road vibrations and harsh conditions while maintaining a low profile under the vehicle chassis.
Each pick in this guide highlights specific strengths and potential limitations to help you choose wisely. Note that product availability and pricing can change frequently, so always verify current details before making your final purchase decision.
Top 3 Picks for Best Magnetic Key Box for under Car
Magnetic Key Box, Hide A Key Holder, Under Car Magnetic Key Storage, Waterproof Hidden Key Box for Outside, Car Key Hider Magnet for Vehicles Travel (MM1 Regular)
4.6Editor score
Waterproof magnetic key holder
Super strong magnetic hold
Undercarriage placement design
Nite Ize Hideout Magnetic Key Box – Waterproof Key Hider – Magnetic Key Holder & Box – Waterproof Key Storage for Spare Keys – Black, Extra Large
4.6Editor score
IPX7 waterproof rating
Neodymium magnets included
3M VHB adhesive plate
Top 10 Best Magnetic Key Box for under Car in 2026 Compared
The following comparison table provides a side-by-side look at the key specifications and features of all ten selected magnetic key boxes. This overview helps you quickly identify which model best fits your specific storage and security requirements.
ProductsSpecificationsEditor scorePrice
Editor's Choice
Magnetic Key Box MM1 Regular
Waterproof magnetic holder
Portable and secure case
Super strong magnets
Undercarriage placement
4.6Editor score
Editor's Choice
ALAZCO Hide A Key Magnetic
2 premium quality magnets
Tough ABS case
Multi-use storage
Jumbo size 4x2x0.625
4.6Editor score
Best Premium
Large Magnetic Key Box Fits Bulky Fobs
Large capacity 8.5×5.9×2.7
Four-magnet mounting
IPX5 weather protection
Dual retention latches
4.3Editor score
Master Lock Magnetic Key Holder 207D
Fits 1-2 keys
Durable plastic build
Sliding cover stop
4.69×2.9×2 inches
4.5Editor score
Magnetic Key Box Under Car With Lock
5 strong magnets
Resettable 4-digit code
Ultra-durable material
3 waterproof bags included
4.2Editor score
Magnetic Key Holder Under Car Splash Resistant
2 Neodymium magnets
60 lbs separation force
4.6×2.8×1.5 inches
Splash resistant with latches
4.7Editor score
Upgraded Magnetic Key Holder Under Car
51 lbs breakaway force
3 neodymium magnets
Safety buckle design
Weatherproof tested
4.6Editor score
Nite Ize Hideout Magnetic Key Box
IPX7 waterproof
Powerful neodymium magnets
3M VHB adhesive plate
Extra large capacity
4.6Editor score
Magnetic Key Box With 3 Magnets
Super strong triple magnet
Waterproof and weatherproof
Rugged ABS plastic
Compact low profile
4.6Editor score
Hide a Key Outside Grey Magnetic Box
2 strong magnets
Waterproof air-tight
Undercarriage placement
Gorilla Box design
4.6Editor score
1. Magnetic Key Box – Best Overall Magnetic Key Box for under Car
Magnetic Key Box, Hide A Key Holder
Dimensions 3.5x2x1 inch
Super strong magnet
Waterproof design
Undercarriage placement
This magnetic key box stands out as a top choice for vehicle owners needing reliable undercarriage storage. With a strong rating and solid waterproof features, it ensures keys remain safe from elements and theft while staying accessible.
Pros
- Highly secure magnetic hold
- Waterproof protection
- Compact and portable
- Easy access design
- Durable construction
Cons
- Limited internal space
- Requires flat steel surface
We may earn a commission when you buy through this link, at no additional cost to you.
The super strong magnet securely attaches to your car without fear of falling off during travel. Its compact dimensions make it discreet yet functional for holding standard keys without adding bulk under the vehicle.
While it offers excellent protection against rain and debris, the internal space is limited to standard key sets. Users should avoid overstuffing it to maintain the secure fit and prevent potential rattling.
Ideal for daily commuters and travelers who need a backup key solution, this box delivers peace of mind. It is a practical investment for anyone seeking a dependable hidden storage option for their vehicle.
Secure Undercarriage Placement
Designed specifically for underneath the car, this box ensures discreet hiding of your keys away from prying eyes and theft.
Weather Resistance
The waterproof design protects your keys from rain, snow, and road spray ensuring they function correctly when you need them.
We may earn a commission when you buy through this link, at no additional cost to you.
2. ALAZCO Hide A Key Magnetic – Versatile Storage Solution
ALAZCO Hide A Key Magnetic
2 premium magnets included
Tough ABS case
4x2x0.625 inch size
Multi-use storage
ALAZCO offers a reliable magnetic key holder designed to prevent lockouts in various scenarios from home to vehicles. Its tough ABS case and large size make it suitable for keys and small valuables alike.
Pros
- Avoids locksmith calls
- Durable ABS case
- Multi-use capacity
- Large jumbo size
- Secure sliding mechanism
Cons
- Plastic may wear over time
- Requires cleaning for magnet adhesion
We may earn a commission when you buy through this link, at no additional cost to you.
The inclusion of two premium magnets ensures a strong hold on metal surfaces. The jumbo size allows for multiple keys or even a small tracking device to be stored securely inside the case.
While the ABS material is durable, it can show wear if exposed to harsh abrasions over time. Users should regularly check the magnet strength and surface cleanliness to ensure optimal adhesion.
This model is perfect for homeowners and renters who need a universal solution for key hiding. Its versatility makes it a strong candidate for those who value capacity and security in a single unit.
Universal Application
Great for hiding keys in home, office, rental vacation homes, garage or car ensuring you never get locked out again.
Extra Storage Capacity
Beyond keys, the jumbo size can hold small valuables, money, notes, and tracking devices for added utility and safety.
We may earn a commission when you buy through this link, at no additional cost to you.
3. Large Magnetic Key Box – Large Capacity Option
Large Magnetic Key Box Fits Bulky Fobs
8.5×5.9×2.7 inch size
Four-magnet mounting
IPX5 weather rating
Four side latches
This large magnetic key box is specifically designed to accommodate bulky key fobs and multiple items. Its robust construction and four-magnet system provide a stable solution for undercarriage storage in various vehicles.
Pros
- Fits bulky key fobs
- Four magnet stability
- IPX5 weather protection
- Secondary zip tie holes
- Durable housing
Cons
- Larger footprint visible
- Not for prolonged submersion
We may earn a commission when you buy through this link, at no additional cost to you.
The IPX5 weather protection ensures contents stay dry from rain and road spray. Four side latches add extra security to keep the enclosure closed during rough driving conditions.
While it offers significant capacity, the larger size may be more noticeable than compact models. Users should inspect seals regularly and dry the box after severe exposure to maintain optimal performance.
Ideal for fleet vehicles or work trucks where larger keys or trackers are common, this box balances size and durability. It is a solid choice for those needing extra room without sacrificing magnetic strength.
Accommodates Large Fobs
The 8.5 by 5.9 by 2.7 inch housing holds bulky key fobs, multiple keys, trackers, cards, and other essentials.
Enhanced Security Features
Four latches help keep the enclosure closed while attachment holes accept zip ties for optional secondary retention.
We may earn a commission when you buy through this link, at no additional cost to you.
4. Master Lock 207D – Best Budget Magnetic Key Box for under Car
Master Lock Magnetic Key Holder 207D
Fits 1-2 keys
Durable plastic
Sliding cover stop
4.69×2.9×2 inches
Master Lock brings reliability to key hiding with this compact magnetic holder. While often used on indoor or garage surfaces, its durability makes it a viable budget option for light outdoor or vehicle frame use.
Pros
- Affordable price point
- Trusted brand quality
- Compact and discreet
- Secure sliding cover
- Reliable magnet
Cons
- Small internal volume
- Not for undercarriage use
We may earn a commission when you buy through this link, at no additional cost to you.
The sliding cover includes a built-in stop to prevent loss, ensuring the lid stays attached during use. Constructed of durable plastic, it withstands regular handling without cracking or breaking easily.
The small size limits storage to one or two keys, which may not suit those with fobs or multiple items. Also note that it is not officially intended for undercarriage placement due to size constraints.
Best for those seeking a trusted brand at a low cost, this holder offers basic security. It works well for emergency keys stored on garage frames or metal surfaces where permanent mounting is not required.
Compact and Simple
Designed to comfortably store 1 to 2 keys with a sliding cover that prevents it from being dropped or misplaced.
Secure Attachment
Attaches securely to any steel surface with a powerful magnet ensuring your keys are safe and accessible when needed.
We may earn a commission when you buy through this link, at no additional cost to you.
5. Magnetic Key Box With Lock – Advanced Security Model
Magnetic Key Box Under Car With Lock
5 strong magnets
4-digit password
Ultra-durable material
3.7×2.4×1.3 inches
This magnetic key box adds a layer of security with a resettable combination lock alongside strong magnets. It is built to withstand complex road conditions while keeping keys safe from unauthorized access.
Pros
- Resettable code lock
- Five strong magnets
- Anti-drop design
- Soft protective padding
- Waterproof bags included
Cons
- Heavier than other models
- Code may be hard to memorize
We may earn a commission when you buy through this link, at no additional cost to you.
The five strong magnets provide a firm fixed on any metal parts under the chassis ensuring the box stays in place. Soft sponge pads inside protect items from friction and damage during transit.
While the lock adds security, it requires remembering a code which might be inconvenient in high-stress situations. The box is also slightly heavier which could impact balance if placed improperly.
Recommended for users needing extra security beyond simple magnets, this box is ideal for high-value key access. It is a great solution for those who want both magnetic stability and a coded lock for peace of mind.
Double Security
Secure combination key hiders come with a 4-digit password that can be reset at will making the hidden key safer.
Protected Interior
Equipped with soft sponge pads and waterproof bags to reduce friction and protect stored items from damage.
We may earn a commission when you buy through this link, at no additional cost to you.
6. Splash Resistant Key Holder – Reliable and Durable
Magnetic Key Holder Under Car Splash Resistant
2 Neodymium magnets
60 lbs separation force
4.6×2.8×1.5 inches
Splash resistant latches
With a high rating and splash-resistant features, this key holder ensures security even in wet conditions. The strong separation force ensures it stays attached to your vehicle even at high speeds or on uneven terrain.
Pros
- High separation force
- Two zip tie holes
- Splash resistant build
- Removable padding
- Durable hard plastic
Cons
- Not fully waterproof
- Padding may limit space
We may earn a commission when you buy through this link, at no additional cost to you.
Two holes at the top allow for zip ties or chains if magnetic attachment is not possible. The dark color helps make the box harder to see depending on where you place it under your vehicle.
While splash resistant, it is not fully waterproof for prolonged submersion so caution is advised during heavy flooding. Padding inside can be removed for more storage but may reduce protection for valuable items.
Best for daily drivers who face variable weather, this model offers great balance between size and security. It is a strong choice for those needing a reliable hideaway spot that can handle splashes and bumps.
Strong Adhesion
With 2 Neodymium magnets the holder can be attached to nearly any metal surface with a separation force of 60 lbs.
Alternative Mounting Options
There are 2 holes at the top of the box for zip ties or a very thin chain lock for alternative hiding methods.
We may earn a commission when you buy through this link, at no additional cost to you.
7. Upgraded Key Holder – Enhanced Protection Design
Upgraded Magnetic Key Holder Under Car
51 lbs breakaway force
3 neodymium magnets
Safety buckle design
Weatherproof tested
This upgraded model emphasizes durability and protection with thicker material and internal padding. It is rigorously tested in all environments including snow and rain to ensure reliability during any weather condition.
Pros
- Thicker durable material
- Soft cushion inside
- Rustproof magnets
- Safety buckle design
- Large storage space
Cons
- Cushion may reduce capacity
- Specific undercarriage focus
We may earn a commission when you buy through this link, at no additional cost to you.
Safety buckles endure repeated bending without detachment ensuring the box remains closed during travel. The removable cushion offers flexibility for those who need more storage space for larger items or multiple keys.
While the cushion adds protection it may limit volume for bulky items. Users can remove it if needed but should consider that items might rattle or scratch without it inside the box.
Ideal for outdoor enthusiasts and fleet managers, this box provides a practical storage case for keys and trackers. It is a robust solution for those who need a reliable hider that stands up to harsh conditions.
Superior Build Quality
Perfect size and thicker than other brands, very sturdy to ensure long-lasting use without wear or tear.
Enhanced Safety Features
Upgraded safety buckles are designed to endure repeated bending without detachment for secure closure.
We may earn a commission when you buy through this link, at no additional cost to you.
8. Nite Ize Hideout – Best Premium Magnetic Key Box for under Car
Nite Ize Hideout Magnetic Key Box
IPX7 waterproof rating
Powerful neodymium magnets
3M VHB adhesive plate
Extra large capacity
Nite Ize offers a premium waterproof box that can be fully submerged without risk to contents. Its powerful magnets and included adhesive plate provide versatile mounting options for various surfaces and vehicles.
Pros
- Fully waterproof IPX7
- Adhesive plate included
- Extra large storage
- Durable construction
- Worry Free Guarantee
Cons
- Higher price point
- Large size less discreet
We may earn a commission when you buy through this link, at no additional cost to you.
The extra large capacity allows for storing multiple keys and additional items securely. As a trusted brand, it comes backed by a Worry Free Guarantee that adds confidence to the purchase for any user.
The higher price reflects its robust build and waterproof certification which may not be necessary for all users. The large size also means it might be more visible under a vehicle than smaller compact models.
Best for those prioritizing waterproof security and brand trust, this box offers peace of mind. It is an excellent choice for vehicles exposed to heavy rain or where extra storage space is a requirement.
Complete Waterproofing
This magnetic key box is waterproof with an IPX7 rating ensuring your contents stay safe and dry in any condition.
Versatile Mounting
Includes 3M VHB adhesive-backed metal plate for attaching the hideout to surfaces where magnets might not work.
We may earn a commission when you buy through this link, at no additional cost to you.
9. Triple Magnet Key Box – Secure Hold Option
Magnetic Key Box With 3 Magnets
Super strong triple magnet
Waterproof design
Rugged ABS plastic
Compact low profile
Equipped with three powerful magnets, this box ensures a maximum-strength hold on any ferrous surface. It is designed to stay firmly attached even on rough roads ensuring your spare key never falls off.
Pros
- Three powerful magnets
- Rugged ABS plastic
- Waterproof protection
- Compact design
- No tools required
Cons
- Smaller internal volume
- Requires clean metal surface
We may earn a commission when you buy through this link, at no additional cost to you.
The waterproof and weatherproof construction keeps your spare car key dry and functional in any extreme weather condition for years. The compact design ensures it won't interfere with driving or become an eyesore under your vehicle.
While the triple magnet system is secure it requires a clean surface to work effectively. Over time debris buildup may reduce adhesion so periodic cleaning is recommended to maintain a firm hold.
Perfect for RV travel or emergency storage, this box is a practical solution for car owners. It is an ideal gift for mechanics or family members who want peace of mind regarding their spare keys.
Maximum Strength Hold
Equipped with 3 powerful magnets providing a maximum-strength hold on any ferrous surface under car chassis or truck frame.
Weather Protection
This key box protects your spare car key from rain, snow, mud, and corrosion keeping it dry and functional.
We may earn a commission when you buy through this link, at no additional cost to you.
10. Grey Magnetic Box – Classic Waterproof Solution
Hide a Key Outside Grey Magnetic Box
2 strong magnets
Waterproof air-tight
Undercarriage placement
Gorilla Box design
The Grey Magnetic Box offers a classic waterproof solution for secure undercarriage storage. Its air-tight seal ensures keys stay dry while strong neodymium magnets keep the box securely in place on any metal surface.
Pros
- Waterproof air-tight seal
- Strong neodymium magnets
- Reliable brand design
- Easy access
- Durable construction
Cons
- Grey color may show dirt
- Standard capacity limits
We may earn a commission when you buy through this link, at no additional cost to you.
Designed specifically for undercarriage placement, it ensures discreet hiding of your keys away from potential theft. The reliable and durable design gives peace of mind knowing keys are safely stored and easily accessible.
While the grey color may show dirt over time, the box remains functional and effective. Standard capacity means it may not fit bulky fobs but is perfect for traditional key sets.
Best for those seeking a traditional waterproof key box, this model provides security and simplicity. It is a solid choice for anyone needing a dependable hidden storage option that stays secure during transit.
Waterproof Air-Tight Seal
Our waterproof air-tight magnetic key box ensures your keys stay safe and dry even in wet conditions.
Secure Magnetic Hold
Features 2 strong neodymium magnets securely attaching to your car without the risk of falling off.
We may earn a commission when you buy through this link, at no additional cost to you.
Buying Guide – How to Choose the Best Magnetic Key Box for under Car
Choosing the right magnetic key box involves evaluating factors like magnet strength, weather resistance, and internal capacity. This guide outlines the key aspects to consider before making a purchase to ensure your keys remain secure.
Magnet Strength and Number
The strength and number of magnets determine how securely the box stays attached to your vehicle under various driving conditions. Look for models with neodymium magnets or multiple magnet points to ensure the box does not detach on rough roads.
Prioritize boxes with high separation forces or multiple magnets to guarantee reliability during high-speed travel.
Weather Resistance and Waterproofing
Since the box will be exposed to rain, snow, and road spray, waterproofing is critical to protect your keys from corrosion and moisture damage. Check for IP ratings like IPX5 or IPX7 to ensure the enclosure can handle harsh weather conditions.
Select a box with a high IP rating to keep your keys dry and functional in any extreme weather condition.
Internal Size and Capacity
Different keys vary in size especially with modern fobs which are bulkier than traditional metal keys. Ensure the internal dimensions are large enough to fit your specific key set without forcing the lid closed.
Measure your keys or consider a jumbo size if you plan to store extra valuables or trackers inside the box.
Locking Mechanisms
Some models offer additional security features like combination locks to prevent unauthorized access beyond the magnetic hold. This is useful if you want an extra layer of security against theft or accidental opening.
Consider a box with a resettable code if you need higher security beyond just a magnetic attachment.
Build Quality and Material
The material of the box should be durable enough to withstand abrasion from road debris and vibration. ABS plastic is a common choice for its toughness but check for rustproof internal components to prevent corrosion over time.
Look for rugged ABS plastic construction to ensure the box resists wear and tear during long-term use.
Mounting Versatility
While designed for undercarriage placement, some boxes offer alternative mounting options like zip ties or adhesive plates for versatility. This allows you to use the box on other metal surfaces or structures if needed.
Choose a box with zip tie holes or adhesive options if you need flexible mounting beyond just magnets.
Discreet Design and Size
A compact and low-profile design helps ensure the box is not easily seen by passersby or potential thieves. Larger boxes might hold more but could be more noticeable under a vehicle or on a frame.
Select a low-profile design to maintain discreet hiding of your keys and reduce the risk of theft.
Brand Reputation and Warranty
Established brands often offer better quality assurance and customer support in case of defects or issues. Check for warranties or guarantees that provide confidence in the longevity of the product.
Opt for brands with a Worry Free Guarantee or strong reputation to ensure reliable support if needed.
How to Use and Care for Your Magnetic Key Box for under Car
To begin, open the box and place your spare keys or valuables inside. Ensure the items are organized neatly so they can be retrieved easily without unnecessary shaking or rattling.
Find a clean, flat ferrous-steel surface under your car chassis or frame. Avoid areas near heat sources, moving parts, or heavy rust to ensure the magnets adhere properly and the box stays secure.
After attaching the box, perform a pull-test before driving to confirm it is firmly in place. Regularly inspect the seal and surface for debris to maintain optimal adhesion and weather protection.
Frequently Asked Questions
Are magnetic key boxes secure enough for undercarriage use?
Yes, when chosen correctly with strong neodymium magnets they are secure enough for undercarriage use. Look for models with high separation forces and multiple magnets to ensure they stay attached during high-speed travel or on rough roads.
Will my key fob fit inside a standard magnetic key box?
Standard boxes may be too small for bulky modern key fobs so check the internal dimensions before buying. Larger models specifically designed for bulky fobs offer more space to ensure a comfortable fit without forcing the lid closed.
How do I clean the surface before attaching a magnetic key box?
Use a cloth and mild detergent to clean the metal surface ensuring it is free of dirt and rust. A clean surface allows the magnets to adhere properly and prevents the box from loosening during vehicle movement.
Can I use a magnetic key box on non-metal surfaces?
Most magnetic boxes require a ferrous-steel surface but some come with adhesive plates for non-metal alternatives. If your surface is not metal, check if the product includes an adhesive option for versatile mounting.
What happens if my keys get wet inside the box?
If your box is not waterproof the keys may corrode or fail so always check the IP rating before purchase. Waterproof models keep your keys dry even in heavy rain ensuring they work when you need them most.
Is it legal to hide keys under my own vehicle?
Yes, it is legal to hide your own spare keys under your vehicle as long as it does not interfere with driving safety. However always ensure the box is securely attached to prevent it from falling off and causing hazards.
How often should I check the strength of the magnets?
It is recommended to check the magnet strength every few months especially after driving on rough terrain or in heavy rain. Regular inspection ensures the box remains secure and your keys stay safe from loss or theft.
Can I store valuables like cash inside a magnetic key box?
Yes many models offer space for cash or tracking devices alongside keys but ensure the box is waterproof. If storing cash use a waterproof bag inside to protect it from moisture or road spray during transit.
Final Thoughts on Choosing the Best Magnetic Key Box for under Car
This guide has explored ten top magnetic key boxes for under car storage ranging from budget-friendly to premium waterproof options. Each model offers unique strengths to suit different needs whether you prioritize capacity, security, or weather resistance.
When making your decision prioritize magnet strength and waterproofing to ensure your keys remain safe and accessible. A reliable box prevents lockouts and provides peace of mind for daily drivers and travelers alike.
Remember that product details and availability can change so verify current specifications before purchasing. Select the model that best fits your vehicle and storage needs for a secure hidden key solution.