New Without Tags Brooks Brothers Blue Supima Cotton Oxford Cloth Button Down Original Polo Shirt. Made in USA.  Some have a Sharpie mark on the neck label, some don't.  If marked label, use stain remover on first wash.  Retail $140. 

Featuring an unlined collar, no chest pocket, mother of pearl buttons, and side seam gussets.  The Brooks Brothers Original Polo Shirt is an iconic Trad / Ivy League style item.

Regent Fit, which is slim.  Approximate measurement across chest at armpit level by neck size:

14.5  20

15     21

15.5  22

16     23.25

16.5  24

18     26.25

19     30  (The 19-35 doesn't seem slim to me, but it measures 30.)

I have a separate listing for the new model OCBD with chest pocket.

I combine shipping.