PRISM and AIR PRISM Solid Brass The Prism offers a sturdy but elegant 2" frame with Thermo-Rite's exclusive "frame inserts." The frame inserts are available in a large selection of finishes that provide a wide variety of designer "looks" from which to choose. The inserts are located on the sides, top and bottom frame panels. The anodized aluminum frame without frame inserts offers a modern custom door at an aggressive price. Plus now, Thermo-Rite's new and exciting Air Prism Draft Option provides a fully controllable air-draft shutter system.