I bought this to use in my trackhoe that has a 12v and 24v plug. I tried it in both plugs and it still didn't get hot at all. Even after an hour I was still able to put my bare hand on the bottom and not get burned. I know alot of people in the reviews said it worked great and got really hot, hence why I bought it, unfortunately mine did not. ☹

Boyfriend used it for work.

I put a bowl of soup in there and gave it an entire hour and it still wasn't hot, only warm. Either I got a defective unit or this thing just doesn't have enough heating power to be worth anything. I decided to upgrade the electrical system in my car to be able to handle a microwave instead of dealing with these rinky-dink electric lunchboxes.