Solid Construction: Each solid electrical wire features a solid copper conductor, is suitable for indoor and outdoor use, and contains a jacket designed to protect from heat, gas, dirt, and moisture. Works With: Conduits and table trays for services, feeders, and branch circuits, as well as machines, tools, appliances, control circuits, and many other wiring needs. Multifunctional: PVC, thermoplastic insulation, and nylon sheath protect against moisture and various temperatures. The inherent strength, hardness, and flexibility of the wire makes it suitable for a variety of electrical wiring systems. Made to Last: Each copper wire is thoroughly measured and prepared to meet the electrical needs of residential, commercial, industrial, and many other clean or harsh installation areas. Carefully Designed: Each THHN, THWN insulated copper wire has been designed to meet and exceed industry standards and requirements.