Caveat emptor review by Geoff on 6/22/2016
First of all, whoever decided these had eighteen inches of chain must have been a man; I measure the chain at 13 inches.
Second, they don't spring closed. They spring open, and you limit how far they open with the screw. I'd love to say its not a bad design, but the truth is, I've yet to manage to get them tight enough that they stay on. Even if I tighten them as hard as I can stand, they still slide right off whatever I put them on before I even make it as far as tugging on them or even moving around much.
Third, the PVC clamp tips are only removable if you don't mind ripping them beyond further use.
All told, I have not found these to be a good design. Buy some clothespins. They work better and and you'll get a lot more of them for $20.