I have the Sto-Fen and doesn't seem to be much rocket science to it so I'm sure a knock off would be fine.


I actually like the Gary Fong's results better but it is very clumsy and doesn't stay on very well. If I'm in a crowded place where I'm getting bumped into, I will take the Sto-Fen. if I'm in a mellow spot I'll use the Gary Fong.