Rexolite® is a unique cross linked polystyrene microwave plastic. Rexolite® is often used for high-frequency circuit substrates, microwave components, and lenses with acoustic, optical and radio-frequency applications. Two different forms were originally available: Rexolite® 1422 and Rexolite® 2200 (2200 is a fiberglass reinforced version of 1422). REXOLITE 1422: Thermoset cross-linked styrene copolymer. Combination of good physical and excellent electrical properties including low loss and stable dielectric constant makes this material suitable for use in microwave lenses as well as for precision components. * Note: Rexolite 1422 meets requirements of L-P-516A (Type E2) formerly MIL-P-77 (Type E-2) REXOLITE 2200 has been discontinued – Thermoset cross-linked styrene copolymer with glass mat reinforcement to provide greater temperature stability and strength. Highly suited for missile and other applications where extreme cold, thermal shock and mechanical stress are encountered. Used principally for printed circuit boards.