This SmartCode 10 electronic lock from Weiser can be locked or unlocked by using the keypad or key from the outside, as well as the turn button from the inside. Featuring SmartKey® technology, you can re-key the lock yourself in seconds in 3 easy steps, which means you can change the key that currently operates the lock for a new key. The keypad is backlit for increased visibility in the dark and turns off after 30 seconds of inactivity. In addition, a customized automatic door locking after 30 seconds will give you peace of mind as you never have to wonder if you forgot to lock your door. This lock includes 16 user access codes and 1 master code option, as well as 2 keys. The lock is easy to install and fits most standard residential doors. Requires 4 x AA batteries (sold separately).