Ser 375 D16 External Threading Holder 3/8" Square Shank Rh External Lay Down Threading Holder For Size 16 Inserts Ser 375 D16 External Threading Holder 3/8 Inch Square Shank Right Hand External Lay Down Threading Holder For Size 16 Inserts Eading Holder For Size 16 Inserts Tmx Toolmex Part #6-Ser-375-D16