1st, Welcome
Next. I'm not sure if its PENS. It is certainly not penis. My acupuncturist uses needles and attaches them to a TENS like unit and lets me"cook" so to speak for about 20 minutes under a heat lamp.
It doesn't assist with areas where I have inflammation but in muscular areas where I have spasms and damage from the inflammation after its through it offers a lot of relief. Best results for me are with my neck and shoulders and some upper spinal areas.
I do this in conjunction with regular massage and at least keep blinding headaches away and unbearble neck spasms as a part of my AS past.
To me the PENS were the hockey team from Pittsburgh.

 

stevec-they also serve who stand and wait