The Aspen Ultrawood 11.5 Ft. W x 15.5 Ft. D Solid Wood Patio Gazebo is a heavy duty composite wood gazebo. The Aspen Ultrawood 11.5 Ft. W x 15.5 Ft. D Solid Wood Patio Gazebo is made of a composite material called Ultrawood that looks very much like wood but lasts longer than wood. The Aspen is a large hot tub enclosure providing room for an 8 foot square spa with room for steps and a small sofa to relax around a hot tub. This west coast designed hot tub enclosure includes a Duraflex PC roof with skylight and 6 sliding tempered glass lockable windows. The entrance consists of 2 large lockable swing French Doors made of heavy duty aluminum and tempered glass.