I can't remember the brand those were now. Last week or so I was researching PIDs as well. I did find the manufacturer of those, but there was zero documentation online anywhere. I would probably steer clear of those and go with the Auber Instruments ones.
IF you really want to save a little cash, I was able to find another one from Sestos that seemed to be pretty good. Check out my other thread about them.
The good thing is they have a manual mode. If you go with those though, make sure to get the D1S-VR
-220 as it is the one with SSR control.