Fatherof3 That is a ball trap device.
Actually that's a chastity cage. A ball trap device only covers the balls as far as I know. So that would be a device in shape of the balls that you can open and close (front and back schield and that is being locked at the base (between testicles and penis) so the part holding it together goes rounf the skin between balls and penis ... it's a bkt difficult to explain. I think most of them are made of lether actually