100% copper wire conductor inside Heavy-duty power adapter cord. Used 10 AWG stranded copper inner wire 30A 250V/7500W, support max 30 Amp loading. Molded with electroplated copper terminal in order to avoid surface oxidation effectively. L6-30P Male for L6 type 30AMP twist lock socket, L6-20R Female for L6 type 20AMP twist lock plug. Length: 12 inch. Color: Black