Southwire | sku: 3569470 Southwire 500 ft. 12 Black Solid CU THHN Wire Southwires THHN and THWN is a multi-purpose building wire used in conduit and cable trays for service, feeders and branch circuits in commercial and industrial applications. It is also used as a conductor in NM-B, UF-B, SER, SEU and MC. Southwires THHN... Log in for pricing