This is a gorgeous sweater vest from Brooks Brothers.

Made of luxurious Supima cotton, it's light green with white trim on the inside collar.

This sweater is in MINT condition. It's guaranteed to be authentic and perfect.

Marked M. 

  Across the back, laid flat and unstretched, the sweater measures 22 inches from armpit to armpit, and 26 inches from the collar seam to the bottom of the back.