The Hat Shaper Derby is a bit different that the Hat Shaper Bowler.  It has a higher flatter crown than the Bowler.  However, like the Bowler Hat Shaper, the Derby Hat Shaper also has an inverted brim.  The brim is meant to be flipped-up in your finished hat. 
 
Hat form made of Acrylonitrile Butadiene Styrene or ABS is a plastic very resistant to impact, an amorphous thermoplastic.  They are excellent for forming, blocking, drying and storing your felt hats. They are very strong and can withstand the process of creating felt hats. They are designed to be used with "steam and heat".
 
Give us a call for additional sizes or questions.
 
Circumf.
Height
X-Small
NA
NA
Small