Do not buy. If you live in a city and clean your car and valve stem every day, you should be fine. I drive a lot, like 36,000 or more a year, and I put them in the car. They discolored and interestingly stuck to the valve stem and couldn't get it off. Since the cap is 8mm I pulled out the rosette and some needle nose pliers and couldn't spend it. Then it blew out the next day, and after trying and failing, the agent took the tire to the shop and had them install a new valve stem. When buying lids, make sure they are plastic or brass wine lids, not metal.