Fingerprint Groups: The lock can add up to 15 fingerprint groups. Download the free app (for Android and iOS) using the QR code in the package and enjoy the smart design to unlock via Bluetooth and share passwords with friends and family. USB Rechargeable: The smart lock is equipped with a 100mAh rechargeable lithium battery. Charging time is about 1.5 hours. A full charge can be used for 4 months (2800 unlocking times). When the battery is exhausted, the smart lock remains locked. Simply connect to a USB power source to recharge. Bluetooth Function: The fingerprint lock can also record who unlocks it, the unlock time, unlock location, and usage time and location in real-time. Connect a smart padlock to a free mobile app via Bluetooth. You can use the APP to register fingerprints, unlock, set authorized users, and view the latest 1000 unlocking activities. Robust Structure: The fingerprint lock body is made of aluminum alloy (AD12 alloy) and the shackle is stainless steel (201 stainless steel). It provides excellent tamper and rust resistance to protect your cabinet or home from thieves.