THE SANDVIK COROMANT BORING HEAD, MODEL 391.38-085 042, IS DESIGNED FOR PRECISE BORING TASKS. IT COMES WITH A CAT 50 SPINDLE TYPE TOOL HOLDER AND INCLUDES VARILOCK NUMBERS A390.4550 63 050M AND 391.38-063 63 070. THE OVERALL LENGTH WITH ALL ATTACHMENTS IS 13 INCHES, WITH A PROJECTION OF 6.25 INCHES FROM THE HOLDER.