STW351 Mens Stetson Natural Packable Wool Blend Ivy Hat Size Medium.  The underside of the bill along the panels inside is orange.  There is some elastic at the front of the bill and some mesh behind the bill.  The inside measurement is 23 1/4 inches.  The wool is fairly heavy and the hat is well constructed and of very good quality and Stetson is a well known and reliable brand of good quality.