ConstructionStranded copper conductors. The insulation shall be either fire retardent ethylene propylene rubber (FREP) or fire retardant cross-linked Polyethylene (FRXLPe). Method 1 - Table K1 color coded, two conductors cabled with necessary fillers to make round, CSPE jacket overall, surface printed.Standards1) Cables meet requirements of ICEA Pub. No. S-66-524, NEMA Pub. No.WC7, Cross-linked Polyethylene.2) Cables pass IEEE-383 ribbon burner flame test.3) Individual conductors pass the VW-1 vertical flame test.4) Individual conductors approved as Type XHHW.5) TC Type Tray Cable per Article 340 of the NEC.