Billet Specialties swivel thermostat housings are constructed of CNC-machined billet 6061-T6 aluminum. They are available for 1 1/4 in., 1 1/2 in., or -16 AN fitting hose connections and will swivel 360 degrees. The flange is sealed at the manifold with an O-ring, eliminating the gasket. Stainless steel hardware is included.