It is a composite tube produced from an extra fine weave (light weight) glass reinforcement combined with an epoxy resin system. RT520X meets the requirements of MIL-I-24768/2, Type GEE and is designed for demanding electrical and mechanical applications that require fine machining. RT520X is suitable for rings, collars, inserts, bushings, cryogenic beakers, flasks or tanks, spacers, insulators, neck tubes, rotor sleeves, and fluid and gas transfer piping and gaskets.