Fingerprint door lock: The development and application of fingerprint technology, bringing ease and pleasure to tedious life.     Keyless entry door lock: Two unlock modes- fingerprint and emergency key, after enrolling your fingerprint, biometrics technology to helps you never carry the key to go out, two mechanical keys just work as emgency key or reserve key.     More Secure and Convenient for your life: It needs 4 pcs AAA (Not included)alkaline batteries, works about 1 year, when it runs out, red light will flash to remind you to change battery.     Standard door locks size: applicable door thickness between 35mm to 55mm (1.4 to 2.2 inch) and the adjustable deadbolt mortise 60mm to 70mm (2.36inch to 2.75inch).Applicable for both left and right-handed doors, an perfect alternative for any standard single cylinder American door latch lock, such as apartment, personal residence, office, etc.     Easy DIY Installation: Fits most standard single-cylinder US doors. The simple installation takes minutes with a screwdriver without extra drilling.          Colour: black     Material: zinc alloy          Package Contents:     1 x fingerprint door lock     1 set x installation accessories          Only the above package content, other products are not included.     Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.