The spacer on the left had studs that failed. This was not a product defect, but a missed step in the instructions. there is the possibility/probability that the studs from the vehicle will stick out from the spacer and contact the wheel before the wheel contacts the spacer face. If this happens, the studs will fail. If you look at the spacer on the right, the face have contact indications on it and the studs did not fail. It would be best if the vehicle studs did not stick out past the spacer face. On my wheels, the difference between the front and rear was the rear was sticking out 1/16th inch more than the front. The rear failed and the front didn't. I am seeing pictures of other failures with no wear marks on the face of the spacers. This isn't a quality issue, it's an installation issue.