Electrical wiring to be run in conduit comes in individual strands, encased in insulation to protect the wire and insulate it from other wires and the conduit. Wires come in ither solid or stranded, depending on the wire size. Bare conductors are available for ground wires only. The insulation is made to take on some rather extreme conditions. Heat-, oil-, gasoline- and water-resistant coatings are all available to help your Insulated electric wire survive.