From the DellaQ website: 

A crochet roll you'll want to own whether you are an avid crocheter or a knitter who has accumulated your grandmother's crochet hooks. The pockets are wide enough to hold the Clover Soft Touch or Addi Swing hooks. Please note, the della Q labels rely on the Craft Yarn Council sizing and include Fourteen lettered/numbered pockets (Sizes US B-N 2.5-10mm), plus two non-lettered/unnumbered pockets.