[Ultra Bright Bike Brake Taillight]A built-in integrated accelerometer ensures accurate brake detection, the rear light will automatically turn to brake modes to warn the car coming from behind when decelerating or emergency braking, great for riding on nights. 4 light modes for your choice: slow flash, breathing flicker, strobe mode and steady on.[Save Your Time]The flashing light will turn on automatically in low brightness and turn off in high-intensity light in Fast Flash and Breathing mode[Saddle Fit & Tube Fit Strap-Install]smart rear light offers two different install systems- Saddle fit aluminum alloy system and tube fit straps, whatever you want to put on-saddle or tubes, bicycle or helmet, easily to install in seconds without any tools[USB Rechargeable Long Llife Battery]Built in 350mAh Polymer lithium battery and Energy-saving designs, the rear bike light run time can be up to 45 hours. The taillight can be easily charged by charging cable via computers, chargers or power bank.[IPX6 Waterproof & Shock Resistant]Rear light cover with anybody aluminum alloy case, not worry about the light will get wet by rain. Has excellent vibration resistance, can be used for any terrain ( Tips: Please turn the light mode to the steady on if you wanna use it in the daytime. because This taillight has a smart light sensing function. Light intensity will be automatically dimmed under strong light to reduce the power consumption).type:AColour:RedMaterial:Aluminum alloyPackage Contents:1 x Bike Tail Light1 x usb cable2 x Mounting bracketOnly the above package content, other products are not included.Note: Light shooting 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.