A:Answer If you mean a support bracket on the outside, then that is a separate purchase. The "window mounting kit" included with the AC is a support bracket across the top of the AC and butting up to the window, the side brackets - accordion expansion panels - one on each side, and some foam insulation strips. If your window sill is wide, as in a house with 2x6 walls or an old house, then you may not need to buy the support bracket. Or you may need it, it depends on the installation window