Size:
There is no size label, but it fits in the range of a large. I tried this on over a tshirt and it was a little snug across the shoulders but fit fine in the body. I normally wear jackets in the mid to larger end of a large. It probably fits best on the smaller end of a men's large.
Measurements Laying Flat:
Armpit to Armpit: 24"
Shoulder to Shoulder: 19.5"
Sleeve Length: 24.5"
Total Length: 25"