- Southwire® SIMpull® THHN® copper conductors are made with soft drawn copper. Sizes 14 through 4/0 AWG use a combination-unilay stranding while 250 kcmil and larger sizes use a compressed copper stranding. The wire is covered with a tough heat and moisture-resistant PVC insulation with an overall nylon jacket utilizing SIMpull® Technology. Available in black, white, red, blue, purple, green, yellow, orange, brown, gray. Also available in striped configurations. Some colors are subject to economic order quantity. Marked as THHN in all sizes. Also marked as THWN-2 in sizes 8 AWG and larger or marked as THWN in sizes 14, 12, 10 AWG. Marked sunlight-resistant in sizes 2 AWG and larger. Sizes 14, 12, 10 AWG are available with SIMpull® technology only in SIMpull® BARREL cable drum or SIMpull® CoilPAK™ configurations.