?4-IN-1?Fingerprint bedroom door lock: fingerprint + password + 2 mechanical keys + APP control, 0.3s recognition, 1s to open the door?100 fingerprints and 50 passwords can be added ?Upgraded large fingerprint sensor?The new 160*160DIP sensor has a 35% larger recognition area than the old 120*120 sensor, making the recognition more accurate and stable. ?USB emergency charging?Fingerprint Door knob It has a low battery alarm function and comes with a USB port for emergency charging.Requires 4 AAA batteries (not included) ?Easy installation?Suitable for left and right doors.The bedroom smart door lock is designed to fit US standard doors with back panel sizes of 2-3/8 inches (60mm) and 2-1/8 inches (70mm), and door thicknesses from 1-1/8 inches to 2"-1/8" (30mm-55mm) ?After-sales support?. Provide responsive customer service within 24 hours, if you have any questions about our door locks, please to contact us for 30-day money-back guarantee, 12-month warranty and lifespan technical support.