WEN Twistlock Adapter in the Generator Accessories department at Lowes.com
Conntek PL530L1430, 30 to 30-Amp Generator Locking Adapter with NEMA L5-30P to L14-30R, Yellow
Amazon.com: Camco Power Grip Camper/RV Generator Adapter | Features a Heavy-Duty 30 Amp Locking Male and Female Connection | Rated for 125 Volts / 3750 Watts (55333) : Automotive
Leisure Cords RV Generator Adapter with 30 Amp 4 Prong Locking Male Plug to RV 50 Amp Female Standard Connector (4-Prong) - Walmart.com
Generator Adapter - 30A 4-Prong Male - 30A Female - 30430GPA – United RV