Progressive EMS PT30C
Bought this last summer for my class c and just moved to a class A. Used it three weekends. Though warranty isn't transferable I don't think they'd offer lifetime if they didn't have confidence in their product.
Progressive Industries Portable Electrical Management Systems (EMS) offer quick and easy RV electrical protection. A true plug-and-play application with no installation required. You will feel secure with multi-mode surge, voltage, polarity, and lost/open neutral protection. Each unit includes a digital display, scrolling continuously through the power source information: voltage(s), current frequency, error code, and previous error code (if applicable). Additionally, the computer is driven by state of the art microprocessors.
Currently on back order from progressive.
$200 including shipping in CONUS.