Received them fairly quickly which I was pleased about. When I installed the first cover, I noticed that air was escaping. So I removed the cap and found that the seal was stuck in the valve stem. I removed the gasket from the stem and screwed the cap on without it. After the bladder test, I removed the fillings from the remaining skullcaps and put them on. The air pressure has not dropped, and surprised that after a week they still work and are not stolen.