Amazon.com: 50 Amp Generator Cord and Power Inlet Box, 20FT Generator Cords 50 Amp,125V/250V Generator Power Cord NEMA14-50P/SS2-50R Twist Lock Connector, Male-to-Female, Black : Patio, Lawn & Garden
Amazon.com: 30 Amp Generator Cord and Power Inlet Box, 15FT Generator Cords 30 Amp,125V/250V Generator Power Cord NEMA L14-30P to L14-30R,Twist Lock Connector : Patio, Lawn & Garden
AC WORKS RV/ Marine Generator Adapter 4-Prong 30 Amp L14-30P Generator Locking Plug to 50 Amp RV/Marine Locking Female Connector ADL1430SS2 - The Home Depot
Superior Electric RVA1624 50 Amp NEMA SS 2-50R 125/250-VAC Generator Power Cord Connector - CS6364