Fear not the crafty safecracking techniques of crackerjack thieves - with this AntiTheft Digital Wall Safe, you"ll keep the crooks at bay and your items where they belong. Burglary resistant heavy gauge steel safe with digital electronic locking system (featuring a re-programmable combination). Designed to fit in standard 2x4 wall construction, with studs 16" on center or expands to accommodate 2 x 6 studs. Roomy with approximately .43 cubic feet of storage capacity, and includes a handy interior light. Smartly equipped with an emergency over-ride key and dual live bolts. Powered by 4 AA batteries (included). You"ll love this heavy gauge steel safe. Shelf and wall mounting hardware included. Internal dimensions of the safe are: 20.62"H x 13.75"W x 2.81"D .