This is a premium bike taillight. The taillight can be easy installed in minutes, and do not need any tools, available for any frame with diameter 22.2-31.8mm. It can any USB device with 2-2.5 , and stays for 6 with high brightness, 11 with low brightness, 16 with blinking. Feature - Color: As shown. - Material: ABS. - Size: About 45x28x25mm. - LED: one piece of 0.5W LED. - Brightness: 5 lumens. - Battery: 3.7V 300mAh Li battery. - Waterproof rate: IP44 waterproof rate. - USB RECHARGEABLE BATTERY - Makes the charging easy and . Your Money on Batteries again! - LED LIGHT - Only one piece LED for the taillight, full angle visible from the back, with high brightness to ensure your safety while is more power saving and can extend the working time. - THREE WORKING MODES - Can change modes according to different riding conditions, ensure your safety in any low brightness conditions. - 2 CHARGE - 16 STAYS - It can any USB device with 2-2.5 , and stays for 6 with high brightness, 11 with low brightness, 16 with blinking. - EASY INSTALLATION & NO TOOLS REQUIRED - The taillight can be easy installed in minutes, and do not need any tools, available for any frame with diameter 22.2-31.8mm. Package list: 1 x BicycleTaillight 1 x Silicone holder 1 x USB cable