Hub centric rings are manufactured so that when they are installed on a vehicle, the wheels are located directly off of the center flange of the brake drum or rotor. If the center bore of the aftermarket rim has a wider bore than the stock, this will assist with aligning the wheel properly prior to installing the wheel bolts. Hub centric spacers are designed to push the wheels out further from the rotor.


This is a ring:



This is a spacer: