My physiotherapist recommended Tens Machine but I had my doubts as over the years I have used different massage tools and the benefit was minimal but this machine is really good., I have used it on my neck, my back, and even on my wrist as I have developed RSI due to over use.
I have tried the various modes, but have found that scrapping (Guasha), acupuncture and massage the best, I do not go over 2 or 3 in intensity as it can get uncomfortable for me.
The voice is pleasant and not too loud or too low (check the video) and very clear.
It has helped me greatly and the best thing is it is so small and portable that I can carry and take it to work. Really a fab machine and I have also found similar gel pads at the local drugstore which makes it convenient in every way , very happy