Budget Pemf-device with changeable frequencies

3-4 years ago while researching emf I came a cross a video with a young man
showing a very reasonably priced frequency generator that could vary its operating freq.

I believe it was priced somewhere around 75-250 dollars
and he gave it high recommendations for pain relief.

Needless to say I remember neither the video nor the product,
does anybody here have any suggestions..?