Like anyone who has bought aftermarket wheels with a universal hub bore and balanced the wheels but still felt some vibration, especially at higher speeds, found that this on the wheel is due. the hub bore does not rest on the rotor hub. My new wheels are 108mm and my F150 is 87.1mm so this adapter fits perfectly. Each ring fitted the wheels perfectly and fitted perfectly onto the rotor hub, so I rode at high speeds for a while and didn't feel the vibration anymore! Will update if anything happens, but so far so good!