The door cam helps keep the door closed in the correct position. The cam is mounted around the door pivot point and is made up of a series of ridges and valleys to help keep the door in position. When you open the door, the cam will raise the door ever so slightly, then drop down into another valley to hold the door open. Then as you close the door again, just before the seal contacts the cabinet, the door will fall into another valley helping to hold the door closed. If your refrigerator uses a door closer, the door should shut all by itself. This part is black in color and made of plastic. This is a genuine OEM part.