This Original Equipment Manufacturer part is the same part that was made & installed by the car manufacturer at the factory where the car was produced.
Some aftermarket heater cores require that the inlet and outlet hose blocks from the old core be removed and reinstalled on the replacement heater core. The o-rings between the hose blocks and the heater core are not included with the aftermarket heater core; order 2 of heater core o-ring #92232-71L00 separately for this purpose if needed.