Hiencetec Fingerprint door lock: Biological fingerprint door handle adopts advanced 360° fingerprint sensor, 99% recognition rate, 0.3 reading fingerprint speed. It can store up to 50 fingers, no more searching for keys or worrying about forgetting them. Easy installation: The smart fingerprint door knob can be easily installed in minutes with a screwdriver, the door lock design is suitable for American standard doors. The latch size is 2-3/8" (60mm) or 2-1/8" (70mm), and door thicknesses from 1-3/8" to 2"- 1/8" (35mm-54mm), Suitable for left doors and right doors. Automatic lock: The smart door lock has built-in sensor detection and automatically locks when your door is closed for 5s. Keep your home safe, even if you forget to lock it sometimes. Emergency charging: The biometric doorknob is powered by 4 AAA batteries (not included). In addition, the smart doorknob comes with a usb-c port for emergency use. But it can't be charged and can only be unlocked