Dimensions are not properly listed. The width with the knobs is about 19", which won't fit in the space under my skoolie. It would have to stick out a couple inches and if someone to wreck into that part of the bus it would knock those knobs off and be a BIG problem.
I bought mine from home Depot which did get shipped to home Depot in a box rather than naked like the reviews of the people that bought it from Amazon. One of the brackets was a little bent but it was easy to straighten out.
There is also no information anywhere on how to mount this thing and I have had a very very hard time finding someone willing to help with it because it's a propane tank and it's dangerous.