Bulova 1922 150 "B"
This is apparently a Ladies pocked watch that was converted to be worn as a wrist watch. No date symbols on the movement and the only serial number is on the case. Currently runs and stops so needs a good cleaning.
Case is 25.78mm dia. 8.16mm thick
Crystal is 19.71mm
With the 20 year warranty on the case I am assuming that it is 10k gold filled