THIS IS A D'ANDREA CAT50 MHD’80 MODULAR TOOL HOLDER, PART NUMBER 41.6.80.01.050.49. IT IS DESIGNED AS A CAT 50 HOLDER. THE OVERALL LENGTH (OAL) OF THE ENTIRE PIECE IS 280MM. IT FEATURES A 180MM PROJECTION, A BODY DIAMETER OF 3.25IN, AND A BORE DIAMETER OF 1.675IN.