"Made of solid stainless steel and not the cheap chromed metal usually made in Pakistan, these magnetic ballstretchers are so much easier to put on and off… No more pinching of the skin, no more hassle with hexagon keys and endless screwing. Thirty seconds max, and you’re done! Now available at Mister B. These ball stretchers have a ring segment that comes out and locks into place with strong magnets. These magnets are so strong that you don’t need to worry, it’s not going anywhere. Solid stainless steel Strong magnets 14 mm thickness Inner diameter 39 mm . Made for the fatter NUT !