With this Digital Door Lock, just key-in the combination and turn to unlock...create multiple codes for multiple users This keyless digital door lock is a lockset that has the digital combination lock built into the doorknob. Programmable door lockset has a waterproof backlit keypad that allows you to create and use multiple codes (up to 15 digits), so you can allocate codes among one or more users. Digital door lock lets you give different people access to your home or office without giving out keys that can be lost. Brushed chrome finish digital door knob fits standard boring and backset. Unlike some programmable door locks on the market, this digital door lock has an emergency external battery to override internal battery failure; requires 4 AA batteries (not included).