These clamps are not for the faint of heart. They look deceptively complicated, but open and close just like clothespins. The mechanisms make sure that the more you pull on the chain, the tighter the clamps get (and they go on very tight to start). They are wonderful for those who love intense stimulation and able able to accommodate larger nipple sizes. These clamps go on and off very easily, but it's important to be careful when applying them. The clamps have nubbed rubber grips that mean business, so applying them too close to the very tip of the nipple will produce pain. The clover clamps are perfect for serious play.