It's powered by a 9-volt battery for up to a three-year battery life. Easy to install, you'll be able to replace your existing lock with a screwdriver in less than 30 minutes--no wiring required--and it fits all standard door preparations (1-3/8- to 1-3/4-inch thickness). The universal latch fits a 2-3/8- or 2-3/4 backset, has a 1-1/8- x 2-3/4-inch round corner strike reinforcer, and its latch faceplate features a 1 x 2-1/4-inch round corner and drive-in option. The exterior measures 3 x 7 x 3.25 inches, while the interior measures 3.25 x 8.25 x 3 inches. This keypad lever comes with two keys, features reversible levers for convenience, and is backed by a limited lifetime warranty on finish and mechanics and a 1-year warranty on electronics.