Electronic Keyless Lock, Function Entry with Key Override, Access Method Push Button Keypad, Mounting Style Cylindrical, Lock Material Metal, Finish Satin Chrome, Series NTB600, Handle Type Lever, Door Thickness 1-3/4 in, Key Override Options Small Format Interchangeable Core, Hand Nonhanded, Network Interface None, Outside Height 8 1/8 in, Outside Width 3 3/4 in, Outside Depth 3 5/16 in, Keypad Material Hardened Plastic, Power Source (4) AA Batteries, Battery Life 20,000 Cycles