True Seal 4.005 1/16 1/16 3/16 Plasma Moly Piston Rings Race winning technology at an affordable price. Superior combustion control in today’s extreme engines. Starting with a plasma moly ring that is barrel lapped for quick seating and long life. Second rings are cast iron reverse torsional twist. The oil ring features a stainless steel expander with chrome plated carbon steel rails. Manufactured in the most popular bore sizes. A true seal for more horsepower and longer life. All applications are file fit.