Has anyone ever used these blades? I have to say, for how difficult it is to find 50mm blades and other surgical blades, it amazes me that around the time these came out, I was able to get knockoffs almost immediately. Gotta tell you though... hard to tell the difference. What really piques my interest is who is making all these knockoffs? How? And where do Ali sellers find these manufacturers? Anyway, for what it's worth, these are good blades but I think I prefer my Schick Prolines.