From what I've seen, Tadashi filters seem to be one-hit only, as in, they tend to break a lot easier than your lens would crack and in turn, having to replace them with every non-critical lens hit or tap can get annoying real quick. Then of course, the occasional time the hit would have actually been critical I guess is when one is thankful to be using them. I have a few friends who use them and although they like to joke about them being unpractical gadgets, it's not like they seem to want to go back either.