Cause terrible tangles and knots in the hair.  Flimsy.
I have a set of Goody hair screws that work amazingly on my daughter's hair.  We have lost a couple of them so I looked on Amazon to replace them.  I saw these for a much better price and you get a lot more of them... But trust me on this, it's worth the money to buy the more expensive ones.  These hair screws are flimsy.  They also have small balls on the ends that are a separate tiny piece that cause the hair to get caught around the balls as they screw in or out.  My daughter was crying as I tried to put it in and then cried even more as I tried to get it back out.  It created the most horrific tangled knot in her hair!  I wondered if it was just that particular screw with the issue, so I tried again with a different one in the package.  Same thing.  My daughter made me promise I would not use these again.  I'll be buying the more expensive ones to keep the tears away.
Rating: 1 stars