These MLS Head Gaskets seal extreme cylinder pressure in high-compression, turbo and supercharged, and nitrous engines. Made from viton-coated spring steel, the two embossed outer layers and inner spacer provide excellent stability and a tight, leakproof seal from cylinder head to engine block. The gaskets withstand shearing forces from bimetal (aluminum/iron) head and cast iron block combinations.*Sold 1 per package