I installed a Progressive Industries hard-wired surge protector last year. It has to be wired between the power feed into the camper and the power center. On our camper I had to remove a panel in the bottom cabinet of the pantry were they ran the wire from the power feed plug to the power center which is under the fridge beside it. I installed the surge protector in that space and ran the wired digital display outside the cabinet. The digital display of the amps is real useful to manage the power useage in the camper.
Nights camped in 2013 - 55, 2014 - 105, 2015 - 63