73.1mm OD to 60.1mm ID Circuit Performance Black Plastic Polycarbonate Hub Centric Rings Hub Ring Outside Diameter: 73.1mm (Must match wheel center bore) Hub Ring Inner Diameter: 60.1mm (Must match your vehicle hub bore) Made for Wheels with a 73.1mm center bore and vehicles with a 60.1mm hub bore. 100% Authentic Circuit Performance Product Precision Machined to stop vibrations and ensure a snug fit every time.