Think of it as plastic wrap for solar cells. STR Holdings owns Specialized Technology Resources, which manufactures encapsulants: extruded polymer sheet and film used to hold solar modules together and protect the semiconductor circuits from exposure to the elements. The encapsulants are sold on a global basis to solar module manufacturers, including BP Solar, First Solar, and SunPower Corporation. In addition, its quality assurance business provides inspection, testing, and audit services used by consumer products retailers and manufacturers worldwide to ensure their products and facilities meet applicable international standards. STR Holdings filed to go public in 2009.