The Felt Derby features a 2 1/8" rolled brim and 4" round crown. The Derby has roan sweatband and bound edge. The derby shape hat is also sometimes known as a bowler style as well.
I ordered a McGill but got a Stetson instead. If I would have known they would send a Stetson I would have ordered a smaller size since Stetson runs bigger. At least the hat a fur felt and I wanted a Stetson as well.