This set contains two MAS1 stop cams, each 29mm high, and is supplied with Allen screws and T-nuts for mounting in the door's C-profile. The stop cam can be increased in height using the MAS-E expansion module. When closed, the roller door rests on the stop cams. These protect the rubber profile and/or the internal optosensors from damage. The height of the cam should be selected so that the hollow chamber containing the optosensor is not compressed, but that the sealing chamber sits flush against the floor.