The MAS1 stop cam is 29mm high and is supplied with an Allen bolt and T-nut for mounting in the C-profile of the door. The stop cam can be made higher by using the MAS-E expansion module. In the closed position, the roller door rests on stop cams. They protect the rubber profile and/or the optosensors on the inside against damage. The height of the cam must be chosen so that the hollow chamber in which the optosensor is located is not compressed, but that the sealing chamber fits snugly against the floor.