Feature:1. 3 IN 1 Unlock Ways: Smart door knob has 3 unlock ways into 1 lock, fingerprint unlock, App control, emergency back up keys, a perfect fingerprint door safety lock to get keyless door entry lock.2. Simple but Smarter and Securer: Smart lock adopts advanced Bluetooth technology, support for Tuya app control, allows fingerprint unlocking, secure lock, help you creat a smarter and more convenient life, guard your family safety.3. Classical Design but Stronger: The door knob extended the classical door knob design, equipped with fingerprint lock funtion and modern App control, a very ideal fingerprint door knob smart lock for bedroom, office, apartments, hotels.4. Easy Installation: The fingerprint door knob fits most door thickness of 3555MM, easily replace existing door safety locks. Open mode is available at any time. In normal state, the handle is set to open mode, so no additional settings are needed. In the open mode, the administrator can lock the door by double pressing their fingerprint or by turning the indoor knob.5. Type C Port Emergency Charging: Emergency power supply prevents inability to open lock due to electricity outage. The lock is equipped with an external Type C emergency charging port that can be powered using a power bank or keys.Specification:Item Type: Smart Door KnobMaterial: Aluminum Alloy, Stainless SteelWeight: Approx. 678g / 23.9ozPassword Capacity: 20 PiecesPower Source: 1 x 3.7V Lithium Battery 400MAH (Built in)Unlocking Methods: Fingerprint, Key, AppApplicable Door Thickness: 35-55MMApplicable Scene: Wooden Door, Office Door, Extremely Narrow Door, Eco Door.Package List:2 x Smart Door Knob1 x Lock Body1 Bunch x Keys (2 Keys)1 x Instructions Manual4 x Short Screws2 x Long Screws1 x Brace Plate1 x Installation Key1 x Brace Plate Cover