It is a tube form manufactured using fine weave glass reinforcement combined with a melamine resin system. It meets the requirements of MIL-I-24768/1, Type GME. RT509F is designed for exposure to arc and flame in electrical applications. It is an environmentally sensitive product, and should not be used in areas of high humidity. It is suitable for applications including inserts, bushings, rings, collars, spacers, insulators, and fuse casings.