Hubcentric rings slide over your hub to ensure your wheels are placing the preasure and weight of the car on the hub and not just the lugs. OEM wheels are made to fit perfectly around the hub. Notice how your stock wheels have no gap between the hole in teh center and the hub? Some aftermarket wheels have larger holes in teh center, so you need rings.

Anyway, talk to the company you're getting the wheels from. They should have a chart or list of the size rings you need. Otherwise, I'd call honda...