A kinetic rear light with built-in accelerometer for intuitive switching between regular and burst mode when decelerating. Part of the CatEye-SYNC family of smart bike lights, it can be synced with up to 7 other CatEye products with complete control available in the CatEye app.CatEyeSYNC - one touch control of up to 7 lightsCatEyeSYNC app - your phone as the control centreBuilt-in accelerometer - automatically turns on High Mode when deceleratingRubber band mountRechargeable battery50 lumens