I ordered one from an electric fireplace supplier on line. I measured the area where I wanted to install the fireplace and ordered a model that would fit with just a small modification to the wood cabinet in the 5th wheel.
I removed two drawers and the area where the radio/CD player was installed.
The fireplace fit perfect.
The fireplace heater/blower comes in handy on those cold mornings. It heats up the living area to a comfortable temperature in a short time. The ambiance of the fake fire and crackling sounds provides a similar soothing that a real fire does.