I did get a TENS 7000. It has dial for power marked 0 thru 8. I don't know how this equates to mA. I have turned the dial to subtle perception of current without pain. It almost feels like a very slight, but rapid pin prick affect on the tragus.
I am not very happy with the ear clips I am currently using. It's very difficult to keep them in place on the tragus.
https://www.healthrising.org/forums...o-use-in-vagus-nerve-stimulation-of-ear.2653/ (click on “Download now” box for pdf of lead prep instructions (top of page, right of article title).