Fingerprint Unlock:Your finger is your key, 1 second quick unlock, register up to 15 different fingerprints, including 2 administrator fingerprints, easy to use. No reset button, only administrator can reset or manage fingerprints. Small Size Metal Padlock:Lightweight padlock with 0.4cm diameter stainless steel lock shackle, (3.2+2.6) x 3.2 x 1.3cm, 0.06kg, inner shackle 2.2cm long, width 1.8mm, made of zinc alloy and the shackle is made of stainless steel for superior cut resistance to protect your Gym locker. Extremely long run time and USB rechargeable:The smart padlock is equipped with low power consumption and a long standby time. 110MAH rechargeable lithium battery can support 6 months standby time and can be unlocked more than 2000 times. When the battery is low, it will turn red, just plug in the USB power or charge it with a power bank. Widely used indoors:The size of the smart lock is so small that you can easily put it in your pocket and it's the best choice if you want to take it to gym, school and fence, tool box, cases, chests, cabinets, etc.