100% fiberglass speaker box made for 12 in speakers. This box was designed with a sphere in mind. If you were to take a sphere and dissect it into 4 equal parts; one of those parts its the base for this design. It measures 30.5 X 15.5 X 15.5 and the airspace is 1.1 cubic feet on each side. available in a ported design and sealed. Can paint any color- just provide manufacturer paint code.