Every slide of the rubber O-rings increases the cruelty!
Place your nipple between the steel bars, then slide the rubber bands toward it. The closer they get, the tighter the pinch. There are six O-rings, so you can arrange them for a tighter pinch, or clamp down on multiple points. Of course you don't need to limit it to nipples. It can stretch far enough to fit around a thumb tip.
Abacus Vice Double Bar Pincher Specs and Benefits:
Note: You get one Abacus Vice (comprised of 2 rods and 6 bands). If you wish to use them on both nipples at the same time, purchase 2.
Size: 8 inches in length
Material: Metal, rubber
A simple and effective pinching device