Fitment: 2009-2017 Lincoln Navigator 2010-2014 Lincoln Mark LT 2009-2017 Ford Expedition 2009-2017 Ford F-150 2009-2014 Ford Lobo Package includes: 1 X Heater Blend Door Actuator The function of the damper actuator: The air door actuator adjusts the air flow direction and intensity by controlling the opening and closing of the air door, so as to realize the circulation and adjustment of the air in the car and provide a comfortable driving environment. The damper actuator needs to be replaced in the following situations: 1. The airflow direction is abnormal. .