NiteRider Sentinel 250 Taillight - Lazer Lane Lights 250 lumens BlackNiteRider Sentinel 250 Taillight. Niterider Sentinel 250 taillight features Lazer Lanes light projected on the ground parallel to the rider to encourage passing cars to give a generous distance when overtaking. 250 Lumen Output (Daylight Visible Flash) Highly Visible Laser Lanes Gives Cyclist Their Own Virtual Lane Group Ride Mode Be seen without distracting fellow cyclists 2 Light Levels 2 Flash Modes plus 3 Laser Lane Modes