Genuine OEM Volvo A/C Refrigerant Line O-Ring, part number 30640904. This O-ring is designed to create a tight seal at the connection point of the A/C refrigerant line, preventing the escape of refrigerant gas. A proper seal is essential for the efficient operation of the air conditioning system. Genuine OEM O-rings are made from materials specifically chosen for their resistance to refrigerant and temperature fluctuations, ensuring a long-lasting seal.