Hat shown is a Ladies Small, however the hat can be knitted for larger sizes too.

Stitch patterns used in this pattern are mentioned in the Pattern Post here:
http://smariek.blogspot.com/2007/04/ariel-hat.html
and also in the Pattern Bibliography post here:
http://smariek.blogspot.com/2007/11/pattern-bibliography.html

Matches Ariel Scarf:
http://smariek.blogspot.com/2007/04/ariel.html
http://www.ravelry.com/patterns/library/ariel-cable-scarf