The 4" Tri Clamp Cap is compatible with all tri-clamp and tri-clover fittings. Caps are usually placed over the open end of valves or tri clamp compatible piping in order to keep it sanitary. Tri clover caps can also be drilled and welded to make other fittings. Having several extra tri clover caps around is always a good idea. These end caps are manufactured from 304 food grade stainless steel.