Whats legal in the USA isnt always legal here. Of course they dont have the nanny state tradition like we do. As i mentioned in another thread, the Indianapolis 500 fans can take there own wood in and build a personal viewing platform, and hundreds do. Can you imagine doing that here at the formula 1 ?!
US attitude to electricity is just different. Mains sockets in bathroom, hairdrier in sink etc etc - no big deal. What surprised me about that adaptor is it needs an OCV on your welder of 110v to be effective, and there ain't too many sets like that about, are there?
If you have a welding set running, its either plugged into the mains anyway, or running off a genny which 9 times out of 10 will have 240 and 110v sockets on it, so why would you need this contraption?
It might have enough voltage to run lights, the highest OCV I ever saw on a diesel welder was 100v.
I don't know how much a power saw or large drill would drop the voltage.
To me, it's more useless than dangerous.
Robert