Southwire® Romex® SIMpull® type NM-B (nonmetallic-sheathed cable) may be used for both exposed and concealed work in normally dry locations at temperatures not to exceed 90 deg c (with ampacity limited to that for 60 deg c conductors) as specified in the 2011 national electrical Code. NM-B cable is primarily used in residential wiring as branch circuits for outlets, switches, other loads. NM-B cable may be run in air voids of masonry block or tile walls where such walls are not wet or damp locations. Voltage rating for NM-B cable is 600 V.