The compatibility for ION Wheel Center Caps are ION 171/ION 174, the replacement number of that are #C101713-0 #MC179N108. This also is a opened end center cap which you can see in the photos.
These ION Wheel Center Caps are for ION Alloy Wheels, such as ION 171, and ION 174. The replacement of that is #C101711-0. Outer diameter---140mm(5.51in), Height---77.5mm(3.05in).
The products for ION Wheel Center Caps only suit for ION Wheel, such as ION 171/ION 174/ION 179. Replacement of that is #C101710-0. Outer diameter---168mm(6.61in), Height---94.5mm(3.72in).