Product Details:
Brand: rockbros 
Name: anti-theft bike thumbprint or lock
Digital printing capability: 20 battery parts: lithium battery 420mah
Using time: total power can be unlocked 3000 times 
Size: about 19*12*3.7cm
Shield material: zinc alloy + abs material hook blocking: aluminium alloy + silicone
Weight: about standard 437g: ansi/incit 378 and iso/iec 19794-2 standard
 
Features:
1. Initially, press any fingerprints to enter the fingerprint recognition port. The green led blinks as you hear two sounds, it will unlock
2. Within five seconds of the release, when the green led is glowing, place the fingerprint that you want to enter pressured the digital fingerprint recognition door for four seconds, you will hear a sound, that means enter the input mode.
3. After the finger leaves, press eight times continuously, and you'll hear one sound at a time. The last time there'll be two sounds, then the finger will go away. After ten seconds, the led will come out and the recording will be completed.