1、Smart sensor chip design, high security, sensitive brake induction, fast response speed. 2、Bright LED lamp beads, high brightness, soft and not dazzling. The angle can be adjusted. 3、Lightweight, compact and easy to carry, efficient and waterproof, without fear of wind and rain. 4、Fully charged in 2 hours and 20 minutes, when the light is always on, the battery life is 10.5 hours. Long-lasting battery life is 33.5 hours. Standby up to one year. 5、If there is no moving bicycle within 180 seconds, the taillight will automatically turn off. Item Type: Bicycle Tail Light Material: Plastic Brightness: 100Lm Built-in Battery: Polymer lithium battery, capacity 500mAh, 1 PC (comes with built-in battery) Power Fully charged in 2 hours and 20 minutes, when the light is always on, the battery life is 10.5 hours. Long-lasting battery life is 33.5 hours. Standby up to one year Features: Waterproof, intelligent light sensing, vibration sensing, USB direct charging, etc 1 x1 x Bicycle Tail Light1 x Silicone Belt1 x USB1 x FilmGuaranteed Satisfaction: Customers are our top priority. If you find any problem with the product, please contact the seller immediately. We strive to provide satisfactory after-sales service.