The Master Lock No. 5406D Portable Key Safe features a 2-3/4in (70mm) wide metal body for durability. The shackle design offers over the door mounting for convenience. Set your own 3-digit combination for keyless convenience and increased security. The flexible cover protects combination dials from weather, dirt and grime; and vinyl coated shackle prevents scratching. The Limited Lifetime Warranty provides peace of mind from a brand you can trust.