Advanced LED rear bicycle light with our custom programmed “Alert” technology, it features our Wide Angle Optics lens that provides up to 270° of visibility and innovative automatic braking sensor. When decelerating, the cycle light will turn solid like a brake light and then provide a distinct flash pattern once stopped to alert riders or vehicles from behind. The light will then change back to its previous output mode once the rider resumes their ride.Its co-moulded construction is super compact, highly water resistant and boasts 5 LEDs for up to 150 lumens of output. With 11 output modes, including a Daytime Flash mode, this rechargeable bike light has got options for any time, day or night. A versatile mounting system attaches to aero or round seatposts and it’s micro-USB rechargeable. This is the ultimate cycling taillight for incredible daytime visibility and superior visibility after dark. Key Features: Custom programmed \"Alert\" technology.,Wide Angle Optics lens.,Max. 150 lumens.,11 Output modes.,Micro USB charging.,Highly water resistant..