Proshift rear derailleur in good shape, although it is missing the part that you need to attach to the derailleur hanger. Jockey wheels spin nicely, and spring tensions are good.
Another thing to note is that this might be a repro version from the 2010s?
Here's a good read
https://www.disraeligears.co.uk/site/precision_billet_proshift_mts_2nd_style.html