【USB Rechargeable】Convenient USB charging port for easy power replenishment. With automatic, fully charged cut-off system, smart charging ensures longer battery life 【Multiple Lighting Modes】Four versatile modes including strong light, slow flash, strobe, and quick flash to suit various riding conditions and preferences 【High Visibility】Bright LED light enhances your visibility during night rides, significantly improving cycling safety 【Versatile Mounting】High-elastic strap design fits various seat post sizes, making it compatible with most bicycles 【Compact and Lightweight】With a product weight of just 24g, this tail light won't add unnecessary bulk to your bike setup 【Durable Construction】Made from high-quality ABS and PC materials, ensuring longevity and resistance to outdoor elements 【Easy to use】Simple control button is located on the top of the light, click the button to change the light mode and cycle through the light mode to turn off Specifications: Product Name: Bicycle Tail Light Dimensions: 7 x 1.9 x 1.7 cm Material: ABS + PC Charging Interface: USB Battery Capacity: 330mAh Single Set Weight: 43g Net Weight: 24g Lighting Modes: Strong Light, Slow Flash, Strobe, Quick Flash Mounting: High-elastic strap for various seat post sizes