A nippleclamp is a sex toy. It is a clamp that is applied to the nipples of a person of either gender. It causes pain by the pinching of the nipple, by the restriction of blood flow, and by the reintroduction of blood flow. Nipple clamps are used in some BDSM activities, such as breast torture. The main types of nipple clamps are the clothes-pin-style clamp, tweezer clamp, clover clamp, and piercing clamp, though any device that applies direct pressure can be used. Clamps are typically used in pairs and often connected by a chain. Weights may be hung from the clamps to amplify the pain by increasing the pressure and pinching. The chain may be wrapped behind a fixed piece of erotic furniture such as a post, so that, when the wearer is prodded to jump or otherwise move suddenly, pain is increased by pulling of the nipples. Another variation involves attaching another chain to the chain, the end of which is connected to a clamp attached to either the clitoris for a female or a cock ring for a male. This variation is known as the "Y clamps" for the shape of the chain linking all three connection points when attached to the body.
Clothes-pin style
A clothes-pin style clamp works like a common household clothes-pin — two short lengths of metal, joined by a spring to keep one end closed; in its simplest form it is made of a crocodile clip. Its serrated jaws are usually covered with removable rubber sheaths to protect the nipple from damage and to reduce pain. This type often comes with screws to adjust the pressure.
Tweezer clamp
A tweezer clamp consists of two short lengths of metal, no more than 5-10 cm in length. The two lengths are fixed together at one end and open at the other end. The open ends are curved slightly to improve their ability to grip the nipple. Typically, it has small 1 cm rubber sheaths over this end to protect the nipple from damage and to reduce slippage. A small ring wraps around the two pieces of metal and is used to adjust the tension. The user places the two sides of the metal head either side of the nipple, then by sliding the ring along the clamp shaft towards the nipple, causes the two halves to close tighter together. Tension can thus be adjusted depending on the location of the ring — the closer the ring is along the shaft toward the nipple, the tighter the clamp.
Clover clamp
The clover clamp, also referred to as a "butterfly clamp", is of Japanese design and provides increasing tension if pulled. The clamp itself is flat, about 5 cm by 10 cm in size. The clamp is applied to the nipple and the spring tension holds the clamp in place. The clamp usually provides a very high pain level, and is usually only used by more experienced users. To increase tension on the nipples, small weights such as fishing sinkers can be attached to the ends of the clamp. As increased pulling tension is applied to the clamp, it will cause the jaws of the clamp to close tighter, depending on the amount of pull pressure. Another method is to use the clamps to keep a person in one place. If a cord is tied from the clamp to a fixed place, the wearer of the clamps cannot move away because the clamps will tighten as they move. Eventually the clamps would be pulled off the nipples but not before considerable pain is felt. If the clamps are left on for too long they can cause nipple irritation.