Use way , Bicycle rear light
Material: Plastic
Light emitting color: Red
Battery: built-in 3.7V 250MAH lithium battery
Light emitting 5models;: Normal(13h) / Strong(6h) / Flashing slowly(12h) / Flashing normal (10h)/ Flashing fast(8h)
Visiable distance 250m
LED type: COB
Waterproof IPX4
Package include:
1 x Bicycle rear light
1 x Elastic band
1 x Mini USB cable