A ball vise, also known as testicle vise is a clamp-like contraption, often homemade, that is fastened around the testicles to apply pressure. Most are adjustable, and the recipient will accommodate greater and greater pressure as the session progresses. Some men will squeeze their balls only enough to feel slight pressure while others are true masochists and will endure tremendous squeezing and great pain.
See also: Testicles.
