JMA Magnetic HIDE KEY BOX Large Size

JMA 'Help Key' Magnetic Hide Key Box - Large Size

The JMA 'Help Key' Magnetic Hide Key Box (part code T2-G) is a simple, practical solution for keeping a spare key accessible without leaving it in an obvious location. The magnetised base lets the box attach firmly to any steel or iron surface — under a vehicle, on the inside of a gate rail, on workshop equipment, or behind machinery — making it easy to hide and quick to retrieve when needed.

At 100 x 55 x 15 mm, this large-format version accommodates most standard door and vehicle keys. It slides open to reveal the key cavity and closes with a secure snap. No combination, no code, no batteries — just a concealed physical location as the security layer. Supplied on a retail display card, it is ready for immediate use or point-of-sale display.

JMA is a well-established Spanish manufacturer of key-cutting equipment, blanks, and key accessories. The 'Help Key' range is distributed to locksmiths and hardware trade outlets across Australia.

Key Features

• Magnetised base attaches to any steel or iron surface without drilling or adhesive
• Large cavity (100 x 55 x 15 mm) fits most standard door and vehicle keys
• Slide-open/snap-closed design — simple and fast to access
• Compact and low-profile for discreet concealment
• Durable black plastic construction
• No batteries, no combination to remember, no electronics
• Supplied on a retail display card — ready to use or display

Suitable Uses

Under vehicles — hide a spare car, van, or ute key in a magnetic blind spot for emergency access when keys are locked inside

Gate and fence rails — store a property access key on the gate structure itself; ideal for trades, deliveries, or family members who occasionally need access

Trailers and caravans — keep a spare hitch or cabin key magnetically secured to the trailer frame or wheel arch

Workshop and machinery — attach to steel equipment housings or machinery to keep a site key accessible to authorised staff without a visible hook or cabinet

Smart lock backup key storage — if your smart lock has a mechanical key override, this is an effective way to store the override key outside the property. See our guide to key hiders for smart lock override keys

Not suitable for — surfaces that are painted, plastic, aluminium, or non-ferrous. The magnet will not adhere to these materials. If your gate or vehicle panel is aluminium or fibreglass, a different key storage solution is required.

Key Hider Range at Terry's

Terry's stocks several magnetic and concealment-style key hiders across different formats and security levels. Choose based on how discreet, how weatherproof, and how hard-to-find you need the hidden key to be.

Available Finish Options

• 
  Black
  (This Product)
  STK T2-G

Finish does not affect function or performance.

Full Specifications

Frequently Asked Questions

Will this fit a modern car key with a large rubber head or transponder?
The T2-G at 100 x 55 x 15 mm is the larger of the two JMA boxes and is more likely to accommodate a larger key head — but modern remote-head car keys with big rubber grips may not fit. If your car key is unusually bulky, check the cavity dimensions against the key before relying on this product for automotive use. The T1-P small version (75 x 45 x 15 mm) is smaller still.

How strong is the magnet — will it hold at highway speed under a car?
JMA does not publish a rated pull force for this product. The magnet is designed for the kind of concealment use described (parked vehicles, gates, equipment) and is a standard retail key hider magnet — not an engineered high-retention magnet. For high-vibration, high-speed, or off-road automotive applications, a product with a specified neodymium magnet rating (such as the FK Surf Key Hider Magnetic) may be more appropriate. When in doubt, test retention at low speed and in a protected position before highway use.

Is it weatherproof? Can I mount it outside?
The T2-G has a slide-close lid that provides basic splash resistance, but JMA does not publish an IP weatherproofing rating for this product. It can handle light outdoor exposure when attached to a sheltered location (under a vehicle, inside a gate frame). Avoid direct, sustained rain exposure or submersion. For outdoor key storage with a confirmed IP rating, consider a wall-mounted key safe such as the Burg-Wachter KS-30 (outdoor-rated, combination access).

Is this suitable for storing a smart lock override key outside the property?
Yes — this is one of the recommended use cases. If your smart lock has a mechanical key override, the best practice is to store that key somewhere on the property — not inside the house. A magnetic key box hidden on a gate rail, under a letterbox, or inside a garden structure is a common approach. Choose a location that would not be obvious to a stranger but that you and trusted contacts can find quickly in an emergency.

What is the difference between the large (T2-G) and small (T1-P)?
The T2-G measures 100 x 55 x 15 mm and is suited to standard household door keys and some car keys. The T1-P is 75 x 45 x 15 mm — better for slim locations where the larger box may protrude noticeably. Both are the same black slide-close format and carry the same retail price.

Additional Information

Location selection is the real security
A magnetic key box provides no mechanical security on its own — anyone who finds it can open it. The security comes entirely from the concealment location you choose. Best locations are not visible from the street, are protected from casual discovery (under the vehicle body, inside a hollow rail), and are accessible to you quickly in an emergency. Avoid obvious spots: under the front bumper centre, on the driver's door sill, and under the letterbox are commonly known locations. Read our guide to key hiders for placement tips.

Magnetic key boxes vs wall-mounted key safes
Magnetic key boxes are best where you need something completely invisible and require no drilling. Wall-mounted key safes (such as the Burg-Wachter KS-30, Carbine CKS-SH-BUT-L, or the ABUS KG747LC) add a combination code barrier so that finding the box alone is not sufficient to retrieve the key. For Airbnb, rental, or higher-security applications, a wall-mounted combination key safe is a better fit — see our Airbnb & Short-Stay Rentals chapter for key access strategies in that context. For best-practice mechanical key storage strategy generally, read the mechanical surf key strategy guide, and see our overview of how surf-style key lock boxes work for a format comparison.

Keyless car entry and relay attack risk
If you are hiding a keyless-entry or smart key fob, be aware that relay attacks on passive keyless entry systems can be a concern in some contexts — the fob does not need to be in your hand for a relay device to extend its signal. This is unrelated to the key box itself, but worth knowing if the key in the box is a keyless-entry fob. Standard cut keys stored in this box carry no such risk.

How this relates to smart lock backup key access
Most smart locks with a mechanical key override cylinder include a pair of override keys. Best practice, as outlined by our locksmiths, is to keep one inside the house and store the second on the exterior of the property in a concealed location — such as this key box — so that you are never locked out if the battery fails and you do not have your phone. For a full explanation of backup key access on smart locks, see our guide to what happens when a smart lock battery dies.