Boring Head Holder, QZST, Overall Length 2.9840 in, Inside Dia. 3/16 in, Bore Dia. 3/16 in, Shank Type - Machining Straight, Shank Dia. 22.00mm, For Use With Star Swiss Machine Models SR-20/SB-16/SB-20R/SR-10J/SR-20J/JN, Finish - Machining Black Oxide