Knit Picks Rainbow Wood Crochet Hook Set (3.5 - 6.5 mm), 7 sizes Includes sizes E-4 (3.5mm), G-6 (4mm), 7 (4.5mm), H-8 (5mm), I-9 (5.5mm), J-10 (6mm), K-10.5 (6.5mm) Each Harmony crochet hook is 6" in length The burnished surface of Harmony wood has a slight grip to easily manage slippery yarns Layers of laminated birch add strength while a deeply grooved hook provides precision control