I bought an electrical stimulation device on Amazon (£40) for my hand cramp and thought it was quite effective, so I gave it a good review, but with suggestions for improvement.
Today I got a response from the product designer, who’s in China, thanking me for the suggestions, and telling me the product has won 7 awards there, but is not widely known outside China.
I’ll not put a link here, because I’m a new member of this forum, but if anyone might benefit I can suggest where to look.