ITEM NAME:LED Smart Bicycle Rear Light Auto Start/Stop Brake Sensing Bike Tail Light Product Description Description: LED Smart Bicycle Rear Light Auto Start/Stop Brake Sensing 6 Modes Waterproof USB Rechargeable Bike Cycling Tail Light Feature: Sensitive smart start/brake sensing, horizontal angle self-adaption; Waterproof design; 48 hours long standby, high brightness lamp beads; One-key switch between manual/smart mode; Long press switch to turn on/off, short press to switch flashing mode; Always on lighting mode is manual mode: not subject to light sensing or riding state control; The remaining five flashing modes are smart modes. Smart sensing mode: Weak light+ riding, tail light on Strong light + riding, tail light off Weak light + cycling, delay 45 seconds and tail light off From weak light to strong light + riding, delay 30 seconds and tail light off In smart mode, you can long press the switch to turn on/off. Specification: Lighting mode: 6 modes (1 manual mode+ 5 smart modes) Product size: 44*34mm/1.73*1.34" Note: 1. There may be slight size deviations due to manual measurement, different measuring methods and tools. 2. The picture may not reflect the actual color of the item because of different photographing light, angle and display monitor. Included: 1 X Bicycle Rear Light.Weak light+ riding, tail light on. Weak light + cycling, delay 45 seconds and tail light off. From weak light to strong light + riding, delay 30 seconds and tail light off. Sensitive smart start/brake sensing, horizontal angle self-adaption;.