For cello, double bass, bass clarinet, contraalto clarinet, contrabass clarinet, bassethorn, and contrabassoon. Wolf Super Endpin fits over the endpin tip and locks down tight with three set screws, one of which is a thumb screw which allows quick removal and reinstallation. The special rubber composition of the ball provides a good grip on almost any surface. With this design, the endpin will not punch through the rubber and mar your floors.