- Southwire Romex® brand SIMpull® NM-B cable is manufactured as 2, 3, or 4 conductor cable, with a bare ground wire. Copper conductors are annealed (soft) copper. Stranded conductors are compressed stranded. Conductor insulation is 90 deg C-rated polyvinyl chloride (PVC), nylon jacketed. Romex® brand SIMpull® NM-B cable is designed for easier pulling, resulting in easier installation. The cable jacket is color coded for quick size identification; white - 14 AWG, yellow - 12 AWG, orange - 10 AWG and black - 8 AWG and 6 AWG.