Multiple Accesses: 4 in 1 biometric door lock that meets daily life. Code unlock 4*Key Fobs and fingerprint unlock - you don't need to carry keys with you or worry about looking for keys everywhere. Mechanical key can be used as a backup key to unlock (in case of emergency such as battery exhaustion) Fingerprint sensor: 508 DPI fingerprint sensor module, 360° fingerprint reading is accurate and fast, supports storage of up to 100 sets of fingerprints, and the recognition rate exceeds 99% within 0.3 seconds. Easy Installation: Keyless entry door lock is designed to fit US standard door, Backset 2-3/8(60mm) and 2-1/8(70mm), door thicknesses from 1-3/8'' to 2-1/8''(30mm -55mm). the lock just with a small screwdriver quickly and easily install. Fit both left handed and right handed doors(Suitable for indoor and outdoor doors). Warm Tips: Fingerprint door knob requires 4 AAA batteries (not included), which can be used for up to 8-10 months depending on the frequ