[Support 3 Unlocking Ways] This smart door knob has 3 kinds of unlocking methods, including fingerprint identification, APP control and emergency key. You can choose the unlocking method freely according to your needs and preferences [Enhanced Security] Fast fingerprint identification unlocking, semiconductor fingerprint sensor, higher security coefficient. Emergency key unlocking: hidden keyhole prevents technical prying of the door lock, in case of emergency, you can use the key to unlock the door [Easy to Use] This fingerprint door lock can quickly recognize your finger and store up to 20 fingerprints. The fingerprint door lock has USB emergency power to unlock the door and low battery alarm function, easy to use, to ensure your home security [Durable and Easy to Install] The smart door lock requires 4 AAA dry batteries (not included). It is made of high quality aluminum alloy, very sturdy and can be used repeatedly. It is very easy to operate, no skill is required to install it [Widely Used] This smart door knob is suitable for 35-55mm thick doors, suitable for wooden/steel doors, perfect for bedroom, home, office, dormitory, storage room, laundry room, etc., Manufacturer: QINGLANG