It's the perfect solution to an everyday problem: valve caps fail. These machined metal caps are strong, have a good burr-free design, an internal washer that helps seat them on the valve stem without leakage, and the threads are precision machined for easy installation and removal. I use them to replace lost caps and I don't care if all the caps on my machines are the same. Even if it's important to you, this pack has enough room for 5 four wheelers, or 4 if you have spare tires (does anyone do more?). Goodbye.