1 piece compact version adapter for 10-30P plug into 14-50 240V outlet. Molded with electroplated copper terminal in order to avoid surface oxidation effectively. Recreational Vehicle 50 AMP 4 prong NEMA 14-50 250V 4-prong male plug. Dryer 3 prong 10-30 female. Used 10AWG conductor inner wire, support max 30 AMP loading. Heavy-duty 100% copper wire conductor inside.