Marinco 124ARV-25 RV Electrical Power Cordset (50-amp 125/250-Volt Receptacle with 30-Amp 125-Volt RV Straight Blade Plug, 25-Feet) its on Amazon.
This is what I use at home. I had the 30amp box already wired up from the popup and TT days.
So i found this cord set and it keeps my heavy 50 amp cord in the camper safe and sound. I run the 15K main AC but have never run both. I dont use anything other than the frig as cold place for can goods.
randy