4.2 LITER. Filter element inner seal. 37.5 x 4mm. A circular disk covered in rubber or plastic with a hole in the center where the edge is sometimes tensioned by a spring that prevents fluid from leaking at the Engine Coolant Outlet Housing. Air Filter Seal. All Required. Engine Coolant Thermostat Gasket. Engine Coolant Thermostat Housing O-Ring. Engine Coolant Thermostat Housing Seal. O-Ring. O-Ring. cover outer. Gasket. Housing O -. hsng o -. Pipe O -. unit. Water Outlet. Air filter. Filter element inner. Included with: Filter element, Thermostat housing, Thermostat unit.