I bought some and love them they fit and cut nicly in both of my rotory cutters I have Martelli at first it was a little tight but second cut smoothed right out and cuts fine. Gave a couple of packs to a friend and she said hers didn't cut didn't fit in her cutter right she has the same one I have. told her to try a different blade that most people loved them and had no problem, don't know if she has or not guess I will call her and see, but for me they worked just fine cut wonderful.