Ravemen NT201 Tail Light Watch Your Back The NT201 is an 80-lumen taillight with a built-in radar that spots vehicles up to 140 meters behind you. It sends alerts to a compatible Garmin, Wahoo, or Hammerhead computer, so you see what's coming without turning your head. The radar covers 40 degrees, so it still works through turns. The light also gets brighter when you brake. Features Radar detection to 140m, alerts you to approaching vehicles with a 40-degree coverage Bike computer alerts, works with Garmin, Wahoo, Hammerhead, and other cycling computers80 lumens, daytime visibility to 1, 600m, a spotlight lens design for strong visibility Brake light alert, automatically brightens when you brake Auto on/off, turns off after 2 minutes stationary and on when it detects movement1400m Ah battery, up to 19 hours of runtime across six lighting modes SPECIFICATIONSIntended Use Road, Commuting, Group Rides Max Output80 lumens Radar Detects vehicles up to 140m, 40deg coverage Modes6Battery1400m Ah lithium-polymer Max Runtime19 hours Charging USB-CMount Seatpost and saddle rail mounts included Dimensions99 x 40 x 26. 8mm Weight70g | Ravemen | Nt201 Tail Light 80 Lumens