The Sinister Diesel Thermostat Housing is a drop-in replacement for the OEM housing, with several advantages. It's anodized billet aluminum construction resists corrosion that often plagues OEM units. The Precision CNC machining and thick base plate ensure a complete seal for years to come. It's finished off in our Signature Sinister Blue to add some great looks to your engine bay. NOTE: This thermostat housing is NOT compatible with Mishimoto thermostats, Features:6061 T6 Billet Aluminum Construction, Longer life with a leak-proof seal, Tough, heat-resistant design, Blue Anodized FinishIncludes:(1) Sinister Diesel Thermostat Housing, (1) O-ring seal.