Got this from a government lab.  Some sticker residue and sticker on front of unit.  Some marker writing (all as seen).  

These are very hard to find on-line.  You will know if you need this or not.  If your unit works, you better get this anyway as a backup.    Did not get to power this on (not the right connections), but this will work or money back. 

I don't know much about these.   But I will try to answer your questions the best I can.....