The best-selling Super Light case is made of high quality styrofoam that is lightweight yet shock resistant to the core of the body. Styrofoam used for housing exterior insulation, has high insulation and low moisture absorption to prevent sudden changes in temperature and humidity inside the case. The outer fabric is made of highly water repellent polyester fabric, and the zipper uses the Aqua Guard water repellent zipper, which prevents rain water from entering the case.