AC WORKS 1.5ft NEMA L14-30P to NEMA L14-20R 20-Amp 4-wire Single To Single Black Basic Flexible Adapter in the Adapters & Splitters department at Lowes.com
parkworld 3 ft. 125/250-Volt 20 Amp Generator 4-Prong L14-20 Splitter Cord NEMA L14-20P to (2) L14-20R Receptacle Y Adapter Cord 885866 - The Home Depot