Men's wrist watches were much smaller in the past. This is a Hebe 17J swiss made vintage wrist watch, not sure what year but my guess would be late 50's or early 60's.
Had some interesting difficulties with this. For one, it is much smaller than working on pocket watches. Secondly, the hair spring came loose from the balance arbor. I had to re-mount this very carefully using my tweezers because i do not have a staking set yet. Amazingly enough this repair worked and this watch keeps excellent time!