THIS IS A SANDVIK COROMANT 3 PIECE BORING SET FEATURING A CAT 50 HOLDER. THE SET INCLUDES A SANDVIK A390.45-50 COMPONENT, A VARILOCK TO VARI SET BORING BAR (PART NUMBER 391 36 50 63 270), AND A VARILOCK MICROBORE HEAD (PART NUMBER 448S-808056-16). THE MICROBORE HEAD SUPPORTS A BORING RANGE FROM 80MM TO 136MM. THE ENTIRE ASSEMBLY, WHEN CONNECTED, HAS AN APPROXIMATE TOTAL LENGTH OF 21 INCHES. THE SET IS DESIGNED FOR PRECISION MACHINING NEEDS.