【View video for Floating Emblem perfromance】 The emblem keep stay and no rotation when the vehicle runing. 【Auto light】Floating caps will generate blue light when vehicle runing speed > 25km/h. Use the kinetic energy of the wheels to generate electricity.No need bettery. 【Pack inculde】4pcs floating center Caps Size :75mm diameter. free tool: one screwdrive 【Simple installation】remove the old center caps and replace with the new caps,provide free tools 【Fit for orignal wheel】100% Fit to orignal wheel.Not fit for refit wheel.Not use for steel wheels with snow chains.