This is a replacement mullion rail for your French door-style refrigerator. You will typically find the mullion rail on the left side refrigerator door. The mullion rail helps to keep the refrigerator door closed. If the door will not close properly or if you notice leaking on your floor, you may need to replace the door mullion. A faulty mullion can gather moisture, resulting in a leak. To replace the mullion, simply disconnect the old mullion from the wire harness and unscrew it. Re-attach the wire harness to the mullion and screw it back into place.