SOLODRIVE LED USB Rechargeable Safety Bike Tail Light-4 Modes LED Rear Lamp light-Waterproof and Suitable High brightness LED, which could reach to 15 lumen, power-saving & long service life 4 modes: normal, flash, slow flash, and explosion flash USB outlet charge port planted auto-power-down mode, only takes 2 hours to be fully charged Product specification: 3"1.2"0.8" Suitable Tube Diameter:0.5"- 1.4"