UL & cUL pending, Heavy-duty for Camper, 100% copper conductor inside. NEMA 14-50P plug is straight style can plugin generator outlet without obstruction. Marine Shore power 4-prongs SS2-50 locking female CS6364 connector, 125 Voltage/ 250 Voltage STW 6AWG/3C+8AWG/1C stranded copper inner wire extension cord, support max 50 AMP loading. Molded with electroplate copper terminal in order to avoid surface oxidation effectively. Max Rate 7500 Watt (125V) / 12500 Watt (250V). Length: 1.5 Feet, 10 Feet, 15 Feet, 25 Feet, 36 Feet, 50 Feet, 75 Feet, 100 Feet.