High quality frosted aluminum alloyThe adjustable clip bow can change the angle of the cushion according to its own requirements to get better riding comfortWith tail lamp design, built-in LED lamp with red light to night riding safetyBrake sensing safety warning: when you are riding normally, the tail light will turn on or off in warning light mode. When you are riding with brake slowing down, the tail light will turn on automatically for 3 seconds500 MAH USB convenient charging, built-in 500 MAH battery, USB interface, various charging methodsMode: brake sensing mode - slow flash - always onBattery: 500mahWorking hours: only brake for about 30 hours, warning light for about 10 hours.Colour:blackMaterial:Aluminum alloySize:30.4 x 350mm Package Contents:1 * Bicycle seat1 * usb lineOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.