THE SIMPLEST AND SAFEST WINDOW AIR CONDITIONER SUPPORT. The revolutionary ACe Brace is attached to the interior of the window frame, completely protected from outside conditions. It provides a sturdy mount you can trust to hold the AC unit firmly in place. Its unique design allows the ACe Brace to blend into the face of the AC unit and adapt to almost any window opening. It prevents an intruder from pushing the AC in from the outside or a child from pushing an AC out from the inside.