The all new Tight Kinetic rear bike light packs a punch with Cateyes Kinetic brake technology. The built in acceleration sensor for Kinetic Mode that automatically changes the light from Low or Flashing mode, to High Constant mode to perform as a traditional brake light.Highly waterproof and durable against vibration, the 2 x AAA batteries gives incredibly long life performance whilst the 360 degrees of visibility give you the confidence to know that you ill be seen and be safe.Key Features:Built-in acceleration sensor to detect deceleration under braking,Waterproof design (Waterproof performance: IPX7),Long battery life of up to 180 hours,Rugged body with resistance to vibration while riding,Achieves 360-degree light distribution,High brightness, low power consumption design using 5 LEDs,Equipped with 3 modes, 2 flashing modes + 1 constant mode,Easy switching between constant and flashing with one button,Mode memory function turns the light on in last used mode,FlexTight™ (SP-11) bracket can be fast and securely fixed to the seatpost and seatstay without tools.,Compatible with clip (C-2) to attach to pocket or bag,2x AAA batteries included,Only 49g.Runtime:Low: Approx. 70 hours,Flashing: Approx. 160 hours,Rapid mode: Approx. 140 hours.*The more frequently the brake (kinetic) mode works, the shorter the operating time.Technologies:Kinetic / Brake Mode: Automatically turns on High Constant mode when slowing down to work like a traditional brake light,OptiCube™: Our proprietary OptiCube™ lens technology maximizes brightness for greater visibility.,Side Visibility: Provides visibility from the side to increase safety.,FlexTight™: The innovative and versatile Flextight™ bracket can quickly and securely fastened to virtually any handlebar or stem with no tools required,Daytime: Can be used in the daytime.,All Weather: Can be used in rainy weather.