【Innovative Built-in Smart Taillight】Features an integrated intelligent taillight with automatic brake-activated high brightness and smart on/off functionality through light and vibration sensors, enhancing safety for night riding. 【Waterproof Construction】Crafted from 600D double-sided black film TPU material, this tail bag offers complete protection against rain and wind, ensuring your belongings stay dry in all weather conditions. 【Secure Three-Point Attachment】Three strong magic tape straps provide a stable and shake-free mounting system, eliminating annoying movements during rides over rough terrain. 【Durable Design】The bag maintains its shape well and resists scratches, providing long-lasting performance for frequent cyclists. 【Compact Storage】With a 0.8L capacity and dimensions of 16*6.5*7.5cm, this tail bag offers ample space for essentials without compromising aerodynamics or bike aesthetics. 【Extended Battery Life】The taillight boasts an impressive battery life of 18-110 hours, ensuring visibility throughout long rides or multiple trips. Specifications: Material: 600D double-sided black film TPU Bag Weight: 108g Taillight Weight: 14g Capacity: 0.8L Dimensions: 16*6.5*7.5cm Taillight Material: ABS+PC Taillight Dimensions: 29*29*22mm Charging Input: 5V-2A USB charging Battery Life: Approximately 18-110 hours Battery: 3.7V 250mAh polymer battery