I bought these caps in September 2021 and then tried removing them last week to adjust the air pressure. To my surprise, I found that the aluminum caps reacted to the brass fittings on my stems and completely melted! I even tried removing it with pliers, nothing came loose. The tire center had to cut the bars, remove the tires, put in new bars and rebalance. After $111.70 (and a day without my truck) I learned a valuable lesson. It would be great if the company would reimburse me for my losses, I can provide a detailed receipt!