Mitutoyo inside Micrometer Head interchangeable Rod Type needs 04GAA285 anvil and 303341 nut for 50 63mm Micrometer 88 70 they provide high excursion with FIR861 they provide high excursion with minimal distortion Manufactured from drop forged chrome vanadium steel with hard wearing rubber grip 141 025 Mitutoyo Inside Micrometer Head Interchangeable Rod Type (needs 04GAA285 anvil and 303341 nut for 50 63mm Micrometer) Wide range of inside measurements possible by combining extension rods and anvils with the measuring heads The sleeve is rotated to adjust the index line position when setting to a length standard 01mm graduations Inside Micrometer