Exposure Boost 2 DayBright & Boost-R2 ReAKT Pack USB-CThe definitive, lightweight front and rear light set for urban commuting or daytime visibility. Utilising the form of the Trace and Trace R lights the BOOST and BOOST R RA offer more Lumens out front, 325 or twice the run time, up to 48 hours, to safe guard the rear; USB charging for convenience, a choice of 6 burn times, DayBright pulse pattern and a specific lens design to ensure that the one LED has the power to penetrate through the urban traffic