The ROCKBROS Q4 Samurai is a smart rear bicycle light designed to increase your visibility on the road. It features an integrated sensor that detects braking vibrations, automatically brightening the light for three seconds to alert drivers behind you. You can choose from three brightness levels and five distinct lighting modes, including a constant red glow and various breathing or flashing patterns in red, blue, and purple. Constructed from a blend of aluminum alloy, ABS, and PC, this compact device weighs only 23g and measures 30 x 38 x 29 mm, ensuring it doesn't add unnecessary bulk to your bike. Its IPX6 waterproof rating means you can continue riding confidently through rain or splashes. The light attaches easily to your saddle or seat post for a secure fit. Power is provided by a 260 mAh battery rechargeable via a Type-C USB port. Depending on the setting you choose, the battery lasts between 8 and 16 hours on high, 15 to 30 hours on medium, and up to 50 hours on the low setting, making it a reliable companion for both short city commutes and longer weekend rides.