Those are the ones used for commercial applications. They are not prototypes but actual working units. I suspect the residential units would be much smaller. The inventor held up a unit the size of small Kleenex box for illustration. I don't know what would be the capacity of something that size.
The company press release says a unit the size of a bread box can produce one full kilowatt of power.
I don't think fuel cell technology will work for our trailers, though. They're not an on-demand kind of technology, like a battery
is. Fuel cells have to be heated to a few hundred degrees to start working, and they stay hot only as long you keep pumping fuel into them. Once they heat up they're very efficient at turning fuel feed stock into electric power, though. It's not carbon-neutral by any means, but if you're gonna generate CO2 while you make electricity it's a very efficient use of hydrocarbon fuels.
The Bloom Box PR mentions that the system can operate on a wide variety of fuel feedstocks. "Biofuel to natural gas," they said. What they didn't mention is fuel cells are very sensitive to contaminants. That means most heavier fuels, like coal and fuel oil which tend to be "dirty," probably won't work well in a fuel cell. That's a pity because the US has only a very few percent of the world's oil and natural gas reserves, but about a third of the world's coal.