This device is installed between the vehicle's hub and the wheel. The hub ring fills in the gap between the vehicle hub and the center bore of the wheel. Ensures a proper fit between your wheel and the hub. Designed to reduce unwanted steering wheel vibrations. Precision machined to minimize vibrations and ensure a secure fit. How to choose the hub ring? Hub rings are sized using two different measurements in millimeters. Notes: The outside diameter of the spigot ring should match the wheel's center bore on the back of the wheel. The inside diameter should match the wheel hub size on the vehicle. Specification: Material: Aluminum Alloy Color: Silver Tone Inner Diameter: (Vehicle Hub Size) 54.1mm / 2.13" Outer Diameter: (Wheel Bore Size) 74.1mm / 2.92" Thickness: 10mm / 0.39" Package Includes: 4 x Hub Centric Ring Motor Vehicle Wheel Parts Vehicle Wheel Parts