1. 0.5s Quick Unlock. With the intelligent fingerprint reader, it takes less than 0.5s to Unlock the lock with your fingerprint. Your fingerprint is the Key, you will never need to worry about forget to bring or lose the key, forget the password like before. 2. Upgraded Up to 30 Fingerprint Group. You can add 2 admin user and up to 30 fingerprint to unlock the lock. Please note: the 1st 2 fingerprint you add are administrator fingerprint and the 3rd to 10th are guest fingerprints, only admin user can delete fingerprints. 3. USB Charging & 3000 Times Unlock. 1.5h Charging time and more than 3000 times unlock when battery is full charged. You can charger the lock with power bank, USB port of your PC, or any other 5V 0.5A USB input. Please note: the lock can unlock about 50 times after the battery is running out, please charge it on time.