Lathe 40 Position Quick Change Tool Post size A1. (Some manufacturers and dealers call this model size A). Can be used on BV20, SINO210V, D240, CQ6125 bench lathe which turning diameter is from 150 to 300mm(6″-12″). One set A1 includes: 1 X 540-100 tool post and locking wrench. Basic body is made of high-quality steel which is hardened and ground. The tool holder is clamped against the basic body by an eccentric cam system The system allows a repeat accuracy of 0.01 mm with 40 possible angular positions of the tool holder. Quick-change tool holders are characteried by their unlimited diversity in the use of lathe tools, drills, reamers and boring bars.