Bushings are used with different rotary tables. Master Bushing MPCH 375 , pin drive, used for 37.1/2 in rotary table; Master Bushing MDSP(MSP) is split structure, pin drive, used for 27.1/2 to 17.1/2 in rotary table; Master Bushing MSS is square drive, used for 27.1/2 to 17.1/2 in rotary table.