Our Fuzion has one of these from the factory for battery cut off.
http://cgi.ebay.com/ebaymotors/Heavy...item19c501e250
I added another to cut off power to the landing gear and rear stabilizers when camping. Going to add one to our other fiver as it does not have a battery cut off.
The Toyhauler we had prior to the Fuzion also had this switch from the factory as well. Never had a problem.