what is this?

Reader Fruity was the first to correctly name this device - on just the 9th comment. Impressive. Honestly, when I found this thing I had no clue. I asked other physicists and none of us were sure. However, I did find the answer. Let me show you my secret. I don't know how old this thing is, but it is old. When I open it, my nose and eyes get all tingly - probably from the mold. Here is that apparatus in the book (tome): I can't show you the whole page because it has other stuff of awesomeness that I want to show you later. But, I can show you the description for that item. I am…
Here is my plan. Post a "what is this" on every Friday until I run out of things. I will post the answer on Tuesday. Maybe we should start keeping points. You get more points for being the first one to get it right. You lose points for getting it wrong. Last week was easy, but I think this is more of an appropriate level. Here it is: Nice - it has a tag, but no part number. Honestly, this one stumped me for a while. If you have any reasonable questions, I might answer them.