Exposure Lights BoostR 2 ReAKT Rear LightA rear light based on the popular Trace R design Offering double the burn time with only a 10 gram weight increase Features a secure quarter turn locking bracket Ambient kinetic technology (ReAKT) to adjust brightness automatically Flaring to 150 lumens under braking or in brighter environments Peloton mode to dim the light when detecting a rider behind TECH SPECS Model BoostR 2 Lumens 150 80 Modes 6 Rechargeable Yes Color Red Weight 45g