Run 1 air conditioner in your 50-amp coach in parks with only 30-amp service. No other adapter needed. Plug the twist-lock adapter into the 50-amp inlet of your coach, then plug the 25', 30-amp extension cord to the power post. 50-amp receptacle rated 125/250-volt; 30-amp plug rated 125-volt. Cord is 10-gauge / 3-wire. USA. Does not provide 50 amp service. | Marinco Park Power 50-Amp Locking Adapter with 25' 30-Amp Cord