Visible manufacturing differences between each cap. they are damn heavy. I know it's solid zinc alloy, but that surprised me. They stayed on my tires with no problem, but I have a thought that due to their weight, they will somehow detach and fly away. β« They are smooth; each has a beautiful shine. The color is also quite understated in a good way. They're subtle and don't stand out unless you look at them, a cool novelty if you pay close attention.β« They're not all made equal. There are noticeable differences between each cast, mistakes if you will, but ones that have been sanded down, so I assume it's within their tolerance. For what they are, I don't think it matters much, but if you're sensitive to such things, it might bother you. All in all a pretty nice piece for Marvel/Iron Man fans. You basically get what you expect.