This flat gasket seals the connection between the oil line and the engine block. It sits at the joint where pressurized oil exits the line to enter the engine’s internal lubrication gallery. A compromised gasket here causes oil leakage, which reduces line pressure and can lead to insufficient lubrication of downstream bearing surfaces. The gasket is manufactured to the original profile so it matches the sealing face geometry of the housing without requiring additional sealant. On reinstallation, clean both mating surfaces and replace the gasket; reusing a compressed gasket will not restore the seal.