The Exposure Zenith Mk1; 2000 lumens, long reaching, wider beam, for an hour and a half or combined with rapid mode change technology, TAP, that you can use the 2000 lumens when cascading down a steep, fast desent or tackling a technical trail and then TAP to lower the lumens and increase the run time.Tap technology allows rider to quickly switch between modes by tapping either the body of the light or the helmetOptimised Mode Selector allows rider to fine tune power and run times for the rideIntelligent Thermal Management prevents overheating and maximizing battery lifeEasy to read Fuel Gauge for monitoring run time