This Endpin Rest for Bass or Cello is the Original Rock stop. It's a nice semi-soft hockey puck a little bigger than 3 1/2 inches and a little more than a half-inch thick. It has ribbing on the bottom to help it stay in place on most any surface. In the center is a generous, rounded 1+ inch golden cup that is almost a half inch deep, easy to aim for and hit even on a dimly lit stage.