Genuine OEM Volkswagen Engine Coolant Pump O-Ring, part number 07Z121041. This sealing ring is designed to create a watertight seal for the engine coolant pump, effectively preventing fluid leaks within the cooling system. It is positioned at the interface of the coolant pump and its mating surface. Made from a durable, resilient elastomer, it weighs 0.0082 kg and has a diameter of 0.056 meters. Using a genuine OEM O-ring ensures the correct material composition and precise dimensions for a reliable, long-lasting seal, critical for preventing coolant loss and engine overheating.