4-in-1: Keyless smart entry lock with 4 unlocking methods: fingerprint, password, mechanical keys, and the TTLOCK app. High security, anti-spy, and more convenient to use. Bluetooth App Control: Supports Android 4.3 and iOS 7.0 and above. This Bluetooth doorknob is compatible with the TTLOCK app, allowing you to remotely control your door, share temporary passwords, and dynamic passwords. Low Battery Reminder: This smart lock features low power consumption and requires 4 AAA batteries (not included). It includes a low battery reminder and a USB interface for emergency charging. Easy Installation: The fingerprint door lock is designed to fit door thicknesses of 35-65 mm/1.38-2.56 inches. No wiring or drilling required. It fits both left-handed and right-handed doors. Fingerprint unlocking: The smart fingerprint lock can identify fingerprints in 1.5 seconds and store up to 50 fingerprints; the error recognition rate is low, and the recognition speed is fast.