I've read that people have had issues with these masks but I think whatever the problem was it's solved now. I've ordered them a few times over and these masks have been consistently good. If you use then as intended, they're great. I do need to twist the elastic once to get it to fit snugly on my small face, though. Good size for teens and women. If you are too rough, if you constantly adjust or if you reuse the mask the elastic may not hold up, but I leave mine alone mostly and they cope well.