All Wheel spacers are not the same! - That's why the spacers that we manufacture are made to much higher, finer tolerances than the "run of the mill" spacers that you would find on your everyday car. To give you an example, all of the critical dimensions on our spacers are machined within 25 microns. That's half the thickness of a human hair! Those tolerances also apply to squareness & parallelism as well as concentricity of the spacer bore to boss. We challenge you to find a higher precision wheel spacer.