Feature: 1. 3 Ways to Unlock: Smart door knob supports to unlock via fingerprint, App control and mechanical backup keys. To provide a more convenient and secure way to get into your home! 2. Smart App Control: The smart lock offers a free app that allows you can add up to 30pcs fingerprints, App lock and unlock, check unlock records, and mute the volumn to provide a more convenient and secure using. (Control within Bluetooth Range.) 3. Switch 3 Mode Easily: Rotate the fingerprint door knob thumb turn in the interior knob from Passage mode, Normal Mode(auto locking) and Privacy mode to go in or out your room as you need. 4. Rechargeable Battery: Smart door knob has 500mAh rechargeable lithium battery built with Type C port supports to charge, almost 3 hours can be fully charged. 5. Easy Installation: The smart door knob can be easily installed with a screwdriver in minutes and fits most US door(35‑55mm door thickness). Please check the dimension before purchasing the smart lock. Specification: Item Type: Door Knob Lock Product Material: Stainless Steel Battery: 500mAh Lithium Battery (Shipped with Built in Battery) Support Unlocking Mode: Fingerprint, Key, APP Total Size: Approx. 7.5x23.9cm / 3.0x9.4in Gross Weight: 691g/1.5lb. Package List: 2 x Door Knob1 x Instruction Manual2 x Key6 x Screws1 x Cylinders3 x Accessories Note: 1. Battery life may vary depending on the frequency of the lock being used, and it is not detachable and can not be replaced. Life time using 100000+ times.2. All data are measured manually, and there are certain errors in the measurement results.