This is a great jacket from PRPS Japan.

Made of 100% cotton denim, it is blue but distressed to white.

This jacket is NEW, with tags. It is guaranteed to be unworn, authentic and perfect.

Marked L, and fits small and slim, more like a M. 

It measures 21 inches armpit to armpit, 34/35 inches from mid-collar to the end of the cuff, and 23 inches from the collar seam to the bottom of the back. (All measurements done across the back with the jacket laid flat). 

Please compare my measurements with a coat you have that fits you well.  You will NOT be disappointed.