Creighton is correct ,
There not really collected In one of your other Post I answered I told all I knew about them and I Own one LOL .
It's the really Small one An lacrosse 54 or 57 it's only 4ft tall
Could it be a light socket
Mine has a light at the top that lights up the bottle door .ill check this weekend as it's in the garage buried behind HUMmm 4or5 machines lol