Look very cool but in practice they are terrible caps. O-rings are deformed and inserted into the caps sluggishly; absolutely nothing like the pictures. Threads are poorly cut and either too tight or unusable. The threads are too long for any standard valve and don't really seal. Only buy them if you don't care if your tires are leaking. I'm giving them an extra star because they look cool and the filaments are metal which is better than plastic at least.