They arrived yesterday and I used them straight away. It wasn't quite what I expected. Feels like plastic and the fit and finish are not as advertised. Several caps are scratched and scratched. Works and rolls easily. You can feel the rubber o-ring making contact with the shaft and compressing it, so that's reassuring. The cost is not bad as you get 20 pieces. I'm about to return it because I expected better picture quality. It just looks and feels like plastic. Again, for the price it's not too bad. It's all caps and it does what it's supposed to do. That's more than 3.5 out of 5 stars.