This is the replacement monitor switch for your microwave. It is black in color and measures approximately 1 inch by ¾ of an inch. This switch monitors the door latch position of your microwave and communicates to the electronic control board whether the latch is open or closed. If the switch is damaged, your microwave may not start, even though the door latch is closed. You can check the continuity of the switch by using a multimeter. Be sure to disconnect the microwave from power before you begin this repair.