Features: Automatic Brake Sensing for Superior Safety: Our smart tail light features advanced intelligent brake detection, instantly increasing brightness when you decelerate or brake, providing crucial-warninsg to following vehicles and significantly enhancing your safety on any ride. Ultra-Bright LED for Maximum Visibility: Equipped with high-intensity LED chips, this tail light delivers exceptional brightness, ensuring you are seen from a great distance, even in challenging low-light conditions, making known to drivers and pedestrians for safer night cycling. Intelligent Lighting Modes & Energy Efficiency: Beyond brake sensing, it intelligently adapts brightness based on ambient light and motion, optimizing power consumption while maintaining optimals visibility. This smart-design ensures longer battery life and a hands-free experience. Sturdy, Waterproof & All-Weather Performance: Constructed with a sturdy, quality casing and waterproof , this bike tail light is built to withstand various weather conditions including heavy rain, ensuring reliable and consistent performance during your outdoor-adventure, come rain or shine. Easy USB Rechargeability & Universal Fit: Enjoy the convenience of USB charging, eliminating the need for disposable batteries. Its versatile mounting system allows for quick, tool-free installation on various seats post sizes and designs, making it a perfect fits for almost any bike. Notice: 1.Actual color may be slightly different from the image due to different light effect 2.Please allow 1-3cm deviation due to manual measurement Material: ABS+PC+stainless steel+ceramic grinding cores Package List: 1x Light