4 Pieces - Hub Centric Rings - 73.1mm OD to 66.1mm ID - Aluminum Hubrings Pls MEASURE your Vehicle Hub AND Wheel Center bore BEFORE BUYING Hub Ring Inner Diameter (Vehicle Hub Size): 66.1mm Hub Ring Outer Diameter (Wheel Bore Size): 73.1mm Made of Aluminum. They will not corrode or melt in a regular condition Designed to Eliminate Vibrations caused by Custom Wheels not centering correctly onto vehicle's hub