Features: Easy installation, Built-in rechargeable battery, Waterproof design, USB straight ahead. Three Modes One-Touch Switching: Always Mode, Blinking Mode, Warning Mode. Specification: Item Name: Rechargeable Smart Helmet Warning Light Item Condition: 100% Brand new and high quality Material: ABS Case Color: Black Light Color: Red Mode: Constant, Fashing, Warning Fitment: Universal Size: 8.8*3.7*1.8 cm Usage: Helmet Tail, Motorbike Tail, Cycling Backpack. Installation: Remove the taillights and remove the velcro surface on the back of the taillights,Remove the white backing protective layer behind the matte surface,Attach the matte backing to the back of the helmet,Fix the thorn surface behind the tail light to the matte surface. Package Includes : 1 x Motorcycle Helmet Warning Taillight 1 x USB Cable Do drop