The outer diameter should be 72.6 mm, but it turns out to be 72.45 mm. The inner diameter is believed to be 56.1mm, but its dimensions are 56.25mm. Both OD and ID are much weaker than they should be. This is not a wheel gauge issue as the original wheel rings measure correctly and fit the vehicle and wheels exactly. The purpose of the hub rings is lost when you use this product. You might as well not use hub centering rings as they do NOT center the wheel on the hub as they provide extra clearance. Spend your money on rings from another manufacturer that have the right tolerance. On the plus side, the seller accepted the return (although these rings should have been thrown in the trash).