The Barska Biometric Door Lock Reversible with Black Handle allows you to safely secure a room with the security of a fingerprint. The perfect security solution to almost any home or office. Ideal for indoor, residential, and commercial use to replace traditional door knob. The Biometric technology allows one to store up to 100 fingerprints with 3 master users as well as (1) seven digit pin code. The fingerprint reader responds quickly to unlock door. The handle can be reversed to accommodate either left or right opening doors. Four AA batteries can last up to one year depending on usage. There is no hardware needed for this stand-alone self-contained unit. Backed by One Year Limited Warranty. Includes external 9V battery port provides emergency power, two mechanical keys, front plate (including rubber gasket), back plate (including rubber gasket), tubular latch mortise, strike plate, strike box, installation template, accessories pack and four AA batteries.