Standard:ul Voltage:600v Capacity:50000 coils/week Tw/thw wires are intended for use as grounding wire and other general purpose power wiring in residential, commercial, and industrial applications. Conductors are solid or stranded annealed or hard uncoated copper. Insulation is a polyvinylchloride (pvc) material applied tightly to the conductor. Surface or indent markings for cable identification Conforms to astm b-3 and ul 83 for copper conductors.