Advanced LED rear light with our custom programmed Alert technology. It features our Wide Angle Optics lens that provides up to 270° of visibility and an innovative automatic braking sensor. When decelerating, the 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 his or her ride. Its co-moulded construction is super compact, highly water resistant and boasts five LEDs for up to 300 lumens of output. With 11 output modes, including a Daytime Flash mode, it's 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 light for the best daytime visibility and superior visibility after dark.