1,2 in 1 Unlocking: The smart door lock supports fingerprint recognition unlocking and mechanical key unlocking, biometric fingerprint unlocking, and 2 mechanical keys for emergency unlocking. 2,Quick Identification: Built in fingerprint identification module, this door lock can identify living fingerprints within 2S, and can store up to 30 fingerprints. The error recognition rate is low, and it has self learning function. 3,Low Battery Alarm: With low power consumption, you can use at least 4PCS AAA batteries (not included). When the voltage is lower than 4.8V, the low voltage prompt will remind you to replace the battery. 4,Emergency Power: Smart door lock will sound an alarm if the battery is low. You can temporarily charge your security lock with a power bank, phone charger, any power source with a USB port. 5,Easy to Use: It is safer and more convenient to use through advanced fingerprint technology, which can identify dry and wet fingerprints, suitable for children and the elderly. Applicable door thickness is 30‑65mm. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.