It looks to be just a taste under 6" long X 2" wide. If you need an exact measurement I'll be happy to check it again in the daylite. Or maybe call the manufacturer?
I don't take the TV down for traveling. It stays up all of the time. Not sure of the layout in your trailer, but it is adjustable vertically if need be.
In the Casita
, it's mounted to the underside of a cabinet. The cabinet is very thin fiberglass. So, I made a plywood insert that goes inside the cabinet to spread the weight