Lube-A-Matic Sizer Die .354 Diameter by RCBS RELOADING PRODUCTSFor use with the RCBS Lube A Matic and Lube A Matic 2 presses and and also works with the Lyman 450 and 4500 Lube Sizer presses. Also helps crimp in the gas check on bullet that require a gas check and as well as lubricating.