It's a medium base 85w mercury lamp. For UV?
Not a probe start.
I don't really know anything else about it, what type of ballast it needs, when it was produced, etc.
this lamp ran at 0.38A at 250V on a aurto transformer wich had an OCV of 400V wich was enuf to ignight it with out a starting electrode. I think this lamp is from the 1940s
By the way Henry please email me......