MEROCA Bike Taillights Bicycle Smart Sensing Brake Light IPX6 Waterproof Led Usb Charging Cycling Flashlight Bicycle Rear Lights Ingratiated brake sensing techniques. COB LED. Full 6061 Aluminium alloy chassis. Automatically turn on/off depending on the light intensity and motion. Automatically switch to sleep mode to save power. Two types of mounting kits can buy (cushion mounting / seat tube mounting). 6 flash modes. 500mAh Li-ion re-chargeable battery. Longer use time USB charging. Charge stage indicate. Compact and Light weight design (48g). IPx6 Water proof. Auto/Manual mode switch*. Note: *Manual mode need to switch on/off the light manually. Specifications: Auto/Manual mode switch*. Note: *Manual mode need to switch on/off the light manually. Working principle Manual mode: manual control switch with brake sensing function; Auto mode: light sensor, vibration sensor, brake sensor. In automatic mode,the tail light is off and there is still a brake sensing function. Package Included: taillight*1 USB cable*1 Bracket*1 Notes: Please check the detail size/model information before purchasing. Due to the different monitor and light effect , the actual color of the item might be slightly different from the color showed on the pictures . Thanks for your understanding. Please allow 1-2 cmmeasuring deviation due to manual measurement. Chat with us should you need any assistance.