Basically, the home model protects the house wiring and ‘anything plugged in to power'. Stand alone devices that are not plugged in are a different story however. They would have to be protected differently.
The vehicle model protects the entire vehicles electrical system (which the computer is part of). They even have an RV model that just plugs into an AC outlet in the RV to protect the entire RV electrical system.
It's all about being able to grab any escalation in power and “immediately” shunt it away before it can affect anything. They have been tested at more than double the military standard. You might also note that military standard protection has been found to be only good for “one' strike. It then is basically destroyed. EMP Shield remains viable and keeps protecting against multiple strikes. I've also been impressed as to how and why it was engineered.
Bottom Line … Capability to shunt excess power so fast that it is handled before anything can be affected is the key. The documentation of the testing is available for personal research.
As I mentioned in the first post, this doesn't pertain to all gear. But home/solar/vehicle protection is something we should definitely be concerned with.