I don't recommend them for initial jewelry, but they're great for enlarging existing piercings. This is really a great set for the price.

I got these for a friend, who says that the smaller-sized ones occasionally slipped through in both directions - from the front, because the flaring wasn't enough to hold them in place, and from the back when the O-rings came off. They may need deeper grooves and wider flares, or maybe he's just a violent sleeper. That said, now that he's up to 6ga, he reports no problems.