Easy installation with just a screwdriver in about 15 minutes, no wiring or professional skills required. Fits both left and right handed doors, adjustable backset of 2-3/8" (60mm) or 2-1/8" (70mm), and door thickness from 1-1/8" to 2-1/8" (30mm-55mm) for broad compatibility. 4-in-1 biometric smart door knob combines fingerprint, passcode keypad, 2 mechanical keys and APP control in one secure system. Stores up to 100 fingerprints and 50 passwords, recognizing in about 0.3s and unlocking in 1s, ideal for families, rental units and shared spaces. Advanced fingerprint door handle uses upgraded biometric technology with 360° recognition, allowing accurate reading from any angle. Delivers a recognition rate over 99% in only 0.2 seconds, greatly reducing failed attempts and enhancing convenience for kids and elders. This fingerprint door knob features low-battery and a Type-C USB emergency charging port, ensuring you are never locked out when power is low. Powered by 4 AAA batteries (not included), offering long-lasting performance without frequent battery replacement or complex wiring., Manufacturer: Ounfhtrttk