They appeared to be the best quality when received and should be stronger than the Ford OEMs which have a reputation for cap breaking and the tab being difficult to remove afterwards. I received them in August 2020, installed them in September 2020 and in less than 6 months half of them have changed color. I don't know why, I don't think they have a coating. I suspect rust in the photos. I thought the Dorman brand had a good reputation, apparently I got a bad batch, or maybe it's not really Dorman?