[FUNCTION]: Replacement air door actuator controls the temperature of air from AC vents and recirculation/ outside air into the interior of the vehicle. [EASY INSTALLATION]: Quick and simple installation for a proper fitment on driver and passenger side. Don't forget to recalibrate you HVAC system after installation. Manufacturer Part Number: 1638200108 Exchange part number: 604-938, 163 of 820 01 08 Compatibility: 1998-2003 for ML320 2003-2005 for ML350 1999-2001 for ML430 2002-2005 for ML500 2000-2001 for ML55 Colour:black Material:ABS Package Contents: 1 x HVAC Heater Blend Door Actuator Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.