This chrome cock cage from Master Series features three differently sized O-rings welded togehter, with which you can ensnare your pet. The largest ring goes around the cock and balls like a normal cock ring. The middle sized ring goes around the balls, providing the wearer with a pressure sensation. The third ring goes around the base of the penis to help you maintain the kind of erection that lasts for extended sessions. The Triad Chamber is perfect for the experienced user who wants a sleek and modern look, but seeks a weighted, more supportive cock ring. Medium rings 4.5 cm - 4 cm and 3.2 cm in diameter. If you normally wear a 4.5 cm diameter cock ring, this would be your size.