Master Bushings can be divided into three kinds of structure, hinged, solid or split. There are two kinds of driving way, pin and square. It is adapted to Rotary Table by size from 17.1/2 to 37.1/2(49.1/2in) respectively. When Insert Bowls is assembled, (Some haven’t Insert Bowls), it can be connected with Rotary Slips and Roller Kelly Bushing that are manufactured accordance with API Spec 7K.