This guide is based on utility field experiences, results of Research Lab tests, and manufacturers' recommendations. the guide deals with composite insulators, which include a core, weather sheds and metal end fittings. The core consists of resin and axially aligned glass fibers. The weather sheds are of polymeric materials. The revision is being done in view of technical advances and service experience in the area of composite insulators. Revision Standard - Inactive-Withdrawn. A guide to the application of composite insulators to overhead transmission and distribution lines is provided. It is based on utility field experience, results of research laboratory tests, and manufacturers 'recommendations. The guide deals with composite insulators, which include a core, weather sheds, and metal end fittings. The core consists of resin and axially-aligned glass fibers. The weather sheds are of polymeric materials.