Description: High quality internal lithium battery,only need about 2 hours to be fully charged while be used for about 12 hours. Long Steady Bright----4 Hours Slow Flash----10 Hours flash in order---12 Hours Strobe Flash----8 Hours 4 modes:Long Bright,slow flash,flash in order and strobe. Specifications: Name: Bicycle Rear LED Light Color: Red/Blue/White Size: 7.5*3*2cm/2.95*1.18*0.79" Material: Plastic Power Supply: USB Charge Waterproof: Yes Lumens: 15 Lumens Package Included: 1*Bicycle Light 1*USB Cable 1*Rubber buckle strap Notes: Due to the difference between different monitors, the pictures may not reflect the actual color of the item. Compare the detail sizes with yours, please allow 1-3cm error, due to manual measurement. Please leaving a message before you give the bad feedback, if the products have some problems. Thanks for your understandings.