The Hughes unit contains some MOV's (metal Oxcide Varisistors) that are the active component in what are commonly called Surge Supressor strips. they offer only very limited surge supression (Actually if a true surge comes along they tend to go into firecracher mode,, THink of a fire cracker when the fuse completly burns out. BANG!!!, I have, as they say "Been there" and speak from observation, though not a Hughes thankfully it still cost me over 100 in replacement parts)
They are very effective on Spikes, that is till they wear out.
You can get "Whole House" surge supressors at most any electrical supplier, Lowes, home Depot, many hardware stores and more. These can be added ahead of any Autoformer. And they are easily replaced, Simpl 3 or 4 wire hookup. It looks like a 'J" box with cover and 2 LED's in the cover. The "Magic" is inside the J-box. (Standard outlet size J-box) I have seen these in RV parks believe it or not. Have one in my electrical bay. (But then I also have a hughes autoformer in there)
Difference between a surge and a spike.
Imagine a water spout. (Fountain) Shoots straight up, about 1" wide. That's a spike
Imagine a good 10' surf.. Now that'... A surge.
Home is where I park it!