UPDATE: got an email that says the following: "The lense you have is not for a camera but for an enlarger. That is the device that is used to project an image from a negative on to photographic paper."
UPDATE 2: "Just FYI the lens you have is an enlarging lens from a darkroom film enlarger used to make photographic prints."
The side that is threaded has the following words written around the lens: "EL-OMEGAR 1:3.5 F=75mm L455-111" Written on the side of it is "Lens made in Japan" and it can be twisted to seven different numbers which say "3.5 4 5.6 8 11 16 22" When you twist it through those numbers inside the lense what looks like a field stop or something changes size.
Since I don't know what to look for I can't really tell you what sort of condition this is in beyond what you can see in the picture. So if you buy it and decide anything at all is wrong with it I'll gladly let you return it for a full refund minus whatever it cost me to ship it.
I don't know how much it's worth so make me an offer, I'll sell it to whoever makes the best offer in the next two or three days.