A BDSM device which includes a strap running through the center of a silicone or rubber ball. The ball is placed in the mouth of the person being gagged to prevent she or he from speaking and to give them something to bite down on in case of pain. You might think of ball gags are the BDSM version of Croakies, with a rubber ball where the glasses should be. They have nothing to do with testicles. Different types of ball gags include those with a solid ball, a ball with a hole or holes that allow for breathing, an O-ring that holds the mouth wide open, a ball with a dildo that sticks out of the mouth, and a bit that the teeth can sink into. There are also ball gags that can be more extreme and it would not be appropriate to describe them in a family-oreinted plubication such as this one.