Exclusive Prefab Option: 5-Sided Sauna-FPF66-5S Our newest product from our prefab department is the exclusive five-sided modular Sauna. Available in a 6'x6' size with 7' ceiling, this beautiful room is a showpiece for home or office. The full glass door and clear glass windows in the two side walls offer a spacious open feeling for the bather. We offer a choice of one of our four clear Western woods for the interior and a choice of Alaska Yellow Cedar or clear Western Red Cedar for the exterior.