Note:Here are 5 different opptions, please check carefully: Type A = only 1 pc taillight Type B = 1 pc Multifunction Holder( with 2000mah battery) Type C = 1 pc Multifunction Holder( with 4000mah battery) Type D = 1 pc Multifunction Holder( with 2000mah battery) + 1 pc taillight Type E = 1 pc Multifunction Holder( with 4000mah battery) + 1 pc taillight Function: bike headlight,bike phone holder,USB charger ,electric bell Material: ABS engineering plastic PS silicone Size: About 12 X 5.3 X 3.8 cm Support mobile phone range: 4 inches - 6.3 inches Color: Black Blue Red Orange Light:Double T6 5W bulb Lumen: 400 lumens Speaker decibel: 130 Speaker wire switch Waterproof rating: IPX-3 Fixing method: 360 degree rotation adjustable, tightenable bracket Lighting mode: Strong light - Weak light - fast flash Battery capacity: 4000 mAh polymer lithium battery Charging time: 5 hours Output current 1A (Can charge ordinary mobile phones for once time) Life Time 2000 mAh: 5 hours of intense light, 10 hours of low light, 10 hours of fast light. 4000 mAh: 8 hours of intense light, 16 hours of low light, 16 hours of fast light. Taillight: 3 modes of light: Full light, Slow flash and quick flash. Powered by: 2 x CR2032 batteries (included) Diameter of lamp holder: 2cm Length of silicone belt: 9.8 cm Package Included(TypeA): 1 x taillight Package Included(TypeB/C/D/E): 1 x 4 in 1 headlight 1 x taillight