The Lezyne Strip Drive Pro Alert 400 Rear is thier most advanced taillight with custom-programmed alert technology. It intelligently adjusts its outputs to signal deceleration and stopping, effectively communicating your actions to traffic and fellow cyclists. The light has ten LEDs and a maximum output of 400 lumens; it is engineered for impressive efficiency and runtime, providing the best beam pattern for optimal light dispersion in even the most challenging conditions. Plus, with an impressive 80-hour max runtime, you can rest assured that this light will last as long as you need it to.