The NiteRider® Sentinel™ 150 incorporates three powerful LEDs to produce a retina searing, daylight visible, 150 lumens. Allowing you to be seen day or night. The Sentinel™ has 5 modes, is USB rechargeable and has a unique safety feature, Laser Lanes! The Laser Lanes mode is designed to project ultra-bright laser lines on the ground, giving the rider their own virtual lane, further increasing visibility. NiteRider Sentinel 150 Rear Light Features: Daylight Visible Flash (DVF) Highly visible laser lanes Class leading ultra bright 150 lumen output All in one, Laser and tail light! Compatible with round and aero seat posts Convenient USB rechargeable Group Ride Mode – be seen without distracting fellow cyclists Easy on and off seat post strap mount with quick release tab FL1 Standard IP64, dust and water resistant