I had this in the 5er and already have one in the camper. Thought someone on here coming to the AZ GTG might be interested.
The Progressive EMS-PT50C Portable RV Surge Protector provides high & low voltage protection, whenever source power falls below 104 Volts, or rises above 132 volts and will automatically shut down power to the RV. Once the AC source rises above 104-volts, or below the 132-volt level the time delay indicator flashes for the preset time and then automatically restores power to RV. Lifetime warranty. Dimensions: 5" W x 16 1/2" L x 5" H
This company is great for replacing or fixing if something goes wrong. I finally learned to cover mine after having to send it in for repairs after hard rains. Many on RV.net recommended it.
This can be hardwired in; I would have bought hardwired to begin with but could not find anyone to wire it for me at the time.
For photo and further info, here is the website:
http://www.progressiveindustries.net/ems_pt50c.htm
Retails $431; online for $351.75; I'm selling for $150.