Pressure hose o-ring. 10.8mm. A seal that prevents oil from leaking out, or contaminants from enteRing the Air Conditioning Evaporator Core. A/C Expansion Valve O-Ring. A/C Line O-Ring. A/C Refrigerant Line O-Ring. ''O'' - N. 'O' - NO.2. Air Conditioning (A/C) Refrigerant O -. Cooler seal. Discharge pipe o -. Evaporator Core o -. Expansion Valve o -. Pressure pipe o -. Suction hose seal. Included with: AC & heater assembly, Discharge hose, Discharge pipe, Front Suction Line, Pressure hose, Pressure pipe, Rear Suction Line.