Cateye Sync Set Core & Kinetic Front & Rear Light SetCateye Sync Core Front Light.With 500 lumens and excellent side visibility, the SYNC Core gives you the power to see and be seen. Can be used alone or – better still – combined with other CatEyeSYNC™ enabled lights for unparalleled levels of 360-degree visibility, day or night.Key Features:Compact and lightweight high power rechargeable headlight (500lm),Excellent daytime visibility in Daytime HyperConstant mode,Superior side visibility,Round beam pattern with OptiCube™ lens technology,Built-in fast recharging circuit,Lithium-ion rechargeable battery,USB rechargeable (Micro-USB cable included),5 light modes * Charging time: 3-6 hrs,Mode memory function,FlexTight™ bracket,Optional helmet mount, center fork bracket and out-front bracket 2 available.Cateye Sync Kinetic Rear Light.With a built-in accelerometer that switches to burst mode as you decelerate, SYNC Kinetic gives you an extra level of defense. Use alone or in combination with other models in the CatEyeSYNC™ family for unparalleled levels of 360-degree visibility, day or night.Key Features:Built-in acceleration sensor for Kinetic mode (Automatically turns on with 50 lumen brightness when bike deceleration is detected),Excellent daytime visibility in Daytime HyperFlash mode,Group Ride mode eye-friendly to team riders behind,Superior side visibility,OptiCube™ lens technology,Lithium-ion polymer rechargeable battery,USB rechargeable (Micro-USB cable included),Low battery indicator,6 modes *Charging time: 2.5h,Mode memory function,Battery Auto Save (The mode automatically changes to flashing when the battery power gets low).*The smartphone CatEyeSYNC™ app is required to pair the lights. Before you purchase, be sure to check to see if your smartphone model is compatible. CatEyeSYNC™ Compatible Device ListPC or Mac with internet connection is required for firmware update of the CatEyeSYNC™ lights.Synchronize all SYNC lights:One touch turns all lights on/off,Synchronized lights connection status indicator.Control with smartphone app:Pair the lights (up to seven lights),Customize light modes,View remaining battery level,Turn on/off the lights,Turn on/off synchronization with other lights,Find me function lets the light flashing by tapping the button on app.