19 strand, single conductor. 600 volts. Used in conduit and cable trays for services, feeders, and branch circuits in commercial or industrial applications as specified in the National Electrical Code. Suitable for use in dry locations at temperature not to exceed 90C. Thermoplastic insulation/nylon sheath. Heat, moisture, oil and gasoline resistant. Also rated THWN-2. CAUTION: WATCH ORDERING UNITS. 500 on a coil.