Features:  High brightness LED bicycle taillights, Built in USB charging automatically cut off chips,  Built in lithium poly battery, Sealed waterproof; Support for mobile power charging.  Highlight energy-saving LED wicks, high brightness, flood a wide range.  USB charging, full power off.  Save the cost of buying batteries.  Long use.  Long battery life.  Have a protective effect on the lights.  High-quality high-capacity lithium battery, you can use 10 hours.  Support mobile power to the taillights charging (shipping does not contain mobile power).  Three lighting modes:  Constant light mode ----- Press the switch once, enter constant light mode, the light is 100% brightness;  Burst mode ---- press the secondary switch, enter the burst mode, the light 100% brightness flashes;  Cycle mode ----- Press the switch three times to enter the cycle mode, light 100% light cycle light.    Specifications:  Size: 44*32*24mm;  Weight: About 80g;  Light mode: Always, burst flash, cycle;  Battery: Rechargeable lithium battery;    Package included:  1x 1x taillights;  1x installation hanging buckle;  1x rubber band;  1x charging cable