a failsafe or self - monitoring sensing edge for an overhead door comprising a channel mounted on the bottom edge of the door having a pair of downwardly extending arms which are spaced . an outer covering of soft material is attached to said channel for enclosing the arms . the covering supports within a rigid member extending upwardly through said arms terminating in an actuating member . on one end of the channel is a light source and the other end is a photoswitch . when the covering is depressed upwardly as a result of an obstacle in the path of the door , the actuating member blocks the light beam and the photoswitch gives off a signal which can be used to terminate or reverse motion of the door .