Designed for use day or night the Cateye Kinetic X2 has a built in accelerometer that detects when you are slowing down & switches the light from flashing to constant to alert other road users. Combined with the brightness & 180 degree visibility of the Cateye Rapid range this smart light gives you extra confidence & visibility. The Cateye Rapid X2 Kinetic is USB (Universal Serial Bus) rechargeable & securely fits to your bike with thick rubber straps for a neat & minimalist look. 3 modes: Constant / Flashing / Rapid Up to 50 lumen output Fixed beam from pulse when stopping COB LED technology Li-Polymer battery 180 degree visibility Complex circuitry allows safe charge & discharge USB (Universal Serial Bus) recharge (2 hrs) O-Ring attachment Battery auto save Low battery indicator Light mode memory