SueJean -
Don't know if you are still looking since your post was 5 days ago, but I did purchase a SurgeGuard Plus Model 40240. I had it installed behind the wall just inside the main entrance to my BH (behind the little coat closet, if you can call a 3" deep closet a coat closet) by Chesapeake RV Solutions who I ordered it through. Inside the coat closet is the digital read-out. It provides ample protection for surge, miss-wired outlets, etc. As others who posted have stated, I am a believer in the insurance protection it provides. You never know what kind of electrical maintenance an RV park observes, and it cost a lot less than the repairs throughout a trailer one could potentially experience. Take care!
Jim