The Master Lock 5400E Key Lock Box can easily hold up to 3 keys (house or car) in a convenient location for regular use or can be portable. Lock in place over the door knob or handle for convenience. Set-your-own 4-digit tumbler combination for convenience and quick access. The key storage door pivots open smoothly and remains attached to the lock body for convenient operation while the moulded body and vinyl coated shackle prevents scratching. The 5400E has a reinforced body that will withstand hammering and sawing, whilst the hardened steel shackle will resist cutting. It is also well protected from the weather, its cover protects the combination dials from dirt and grime. All Master Lock products with a locking mechanism have a Lifetime Warranty against mechanical failure. Specification Internal Dimensions: 68 x 78 x 34mm.External Dimensions: 90 x 101 x 40mm.Shackle: Diameter: 10mm, Clearance: 36mm, Width: 47mm.