Description: Intelligent and Creative Bicycle Taillight: This LED bicycle light features an expressive taillight with a battery capacity of 400mAh, charging input of 5V0.28A, and a waterproof rating of IP66. It can last approximately 35 hours for slow flashing low brightness modeBrake Sensing Function: The Bike Rear Light automatically activates a bright red LED warning to vehicles behind when it braking action, ensuring your security on the road. It intelligently detects cycling and will automatically go into sleep mode after detecting 2 minutes of inactivity, saving energy while providing convenienceCustomizable Display: Connect to the APP to customize the display pattern, animation, scrolling barrage and more on the light's 244 matrix pixel points. Create a unique expression that's surely yoursVersatile Applications: This bicycle taillight is great for various scenarios such as exploring, night running, hanging on backpacks or even walking your dog anytime and anywhereMaterial & Compact Size: Made from ABS PC material, with Bicycle Intelligent Expression Taillight dimensions of 4 cmx4 cm/1.57 inchx1.57 inch for durability and compactness. Package includes 1 light, 1 charging cable and a set of installation accessories Specification: Material:ABS PC Size Chart: 4cmx4cm/1.57inchx1.57inch Package Includes: 1 Bike Rear Light1 Cable1 Set Installation Accessories Note: Please allow slightly errors due to manual measurement and different monitors.