Ensures the pump remains sealed and securely mounted to the engine block to circulate coolant and prevent overheating. This stainless steel mechanical fitting, or adapter, facilitates a leak-free connection between the pump's housing and the engine, enabling it to constantly pump coolant through the radiator, keeping the engine at an optimal temperature. Kit includes the stainless steel adapeter, clamp and ring. This fitting is no longer available through BMW so better get one!