These are replacement gaskets for a 4″ camlock fittings. These gaskets are made of Viton A, as a result, they are recommended for aromatics, hydrocarbons, liquid chlorine, carbon disulfide and molten sulfur. Viton A is not recommended for esters or the ketone family. This compound should offer good service -40°F to 400°F. This makes these gaskets the perfect camlock coupling gasket. These gaskets are priced and sold in packages of 10 gaskets.