Left. Right. Separator o-ring. A round Ring used to seal between the Fuel Evaporative Emission Control Vapor Separator and its mounting surface. A seal that prevents oil from leaking out, or contaminants from enteRing the PCV Hose. Engine Coolant Thermostat Housing O-Ring. Engine Crankcase Vent Valve Seal. Crankcase tube o -. Engine Coolant Thermostat Housing O -. Engine Crankcase Vent Seal. Flange o -. PCV Hose O -. Separator o -. Vapor Canister Purge Assembly O -. Included with: Flange, Separator.