The ultraEco external 20% film is designed to be installed on the external surface of the glass where internal installation is not possible. It offers the highest possible heat rejection available on the market and dramatically reduces heat gain. The down side to this film is that is has a reflective internal surface which will cause reflection internally when the sun goes down. It will also have a shorter life span then the Internally installed version of UltraEco. Although, if the film itself is protected by an eaves or is installed in a wind blocked area its life span is dramatically increased. Due the the large amount of heat rejection and solar heat gain, this externally installed film will pay itself off within a short period of time with the minimized use of energy via Air conditioning systems and not to mention the 99%+ U.V. rejection. Roll length is 30.5m. Pre-cut available in any length, by the roll widths available.