18 gauge 2 conductors solid bare copper wire with .011" Foamed polyethylene insulation, non-shielded. Overall .015" gray polyvinylchloride jacket. Cable is made in accordance to UL standard 444, NEC listed Type CM & UL standard 14, NEC listed type CL3 & UL standard 1424, NEC listed type FPL C(UL) 60’C California State Fire Marshall Approved Suggested working voltage: 300V