The Master Lock No. 5400THC Portable Lock Box features 3-1/4 in. W (83 mm) metal body for durability. The portable design offers removable over the knob installation. Set your own 4-digit combination for keyless convenience and increased security. The shutter door protects combination dials from weather, dirt and grime and molded body and vinyl coated shackle prevent scratching. The Limited Lifetime Warranty provides peace of mind from a brand you can trust. Features: Protective weather cover prevents freezing and jamming Large internal cavity prevents jamming, even when holding multiple keys Molded body and vinyl coated shackle prevent scratching Internal dimensions: 3-1/2 in. H (89 mm) x 2-3/4 in. W (70 mm) x 1 in. D (25 mm) Click here for more information on Electronic Recycling Programs