Hand Cramp - TENS product

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.

Still with the hand cramp, I’ve this week bought a pneumatic hand massager machine (£80).

It looks like a round sandwich toaster and at least provides a distraction.