The Master Lock 5423D Lock Box, Resettable Push Button Combination features a 3-1/8 in. (79 mm.) wide metal body for durability. Wall mount lock box design offers permanent installation. Set your own combination up to 12 letter, number or both character combination for keyless convenience and increased security. Lock box's protective weather cover prevents freezing and jamming, while the molded bumper and vinyl coated shackle prevent scratching. Master Lock's Lifetime Guarantee provides peace of mind from a brand you can trust.