Three way fridge

Johnny Hurryup wrote:
I've seen some of the newer RVs have "Three way refrigerators" 120V...12V and gas. I've had the typical 2 way (120V and Gas) wht's up with the third?

3-way fridges have been around for decades, mainly in folding trailers and truck campers. Most are dorm fridge sized, because the tow vehicle charging wire can't keep up the battery's charge, if the fridge was bigger.
Our 1970 Starcraft popup had a 3-way fridge. That's 50 years ago.