Double slotted adjustable top fixture, 12 gauge steel, residential grade. The double slot gives you more adjustment range than a single-slot bracket, which helps when the roller needs to sit in a specific spot to track properly. Mounts at the very top of the door and guides it into the vertical track. If your door's catching or binding at the top of its travel, a new top fixture with more adjustment room can fix that. Sold individually. This is the residential version so it's lighter than the commercial adjustable top bracket.