1 piece Adaptor for generator L14 20A to L14 30A home transfer switch or house panel. Generator L14-20, 4-prong 20 AMP locking male plug. Generator L14-30, 4-prong 30 AMP locking female connector. Molded with electroplate copper terminal in order to avoid surface oxidation effectively. AC Power Adapter L14-20P to L14-30R 125V/2500W, 250V/5000W. Test electrical function by UL & cUL standard. Heavy-duty round power 1-piece adapter plug for generator, 100% copper conductor inside. Yellow with lighted.