Narrow operator reinforcement bracket in white, fits 21-inch door sections and can be field-trimmed down for 18-inch sections. This ORB reinforces the spot where the opener arm attaches to the top section of the door. Without one, the opener pulls on just the panel skin, which eventually dents or tears the steel. includes the clevis pin and cotter ring for the arm connection. White finish matches most standard residential doors. When your existing ORB is cracked or the panel around it is wallowed out, it is time for a new one. Check your section height to pick the right size.