Features1COB lighting chip and PC lens, bright light but not dazzling, 22PCS COB red main light source. 2During cycling process, when tail light senses braking action, will displayed with maximum brightness. 3IP65 waterproof and shockproof, adopts PC, good touching of brake taillight, beautiful appearance, splashproof from any angle. 4Professional manufacturing, fine workmanship, sturdy, durable and long service life. 5Two colours and two types for you to choose, to meet different needs and requirements.SpecificationItem Type: Mountain Bike TaillightMaterial: PCOptions: Seatpost, CushionBattery: Lithium Battery 300mahEndurance: About 20 HoursVisual Distance200mWorking Mode: Constant Bright, Breathing, Flashing LightWaterproof GradeIPX6Size without Rear Cover: Approx. 4x2.7cm/1.57x1.06inchDescription: L1 integrated speed sensor, can detect brake action of the bicycle and automatic switch to brake light mode to prompt the rear car to pay attention. Simultaneously, L1 detects ambient brightness and movement, automatic turn on and off lights, users do not need to care whether the tail lights turned on before riding.Package List1 x Bike Taillight withRear Cover1 x Manual1 x USB Cable