From the Knit Picks Website:
This fun and comfy Aran earflap hat can be knit in Knitpicks City Tweed for an interesting, soft texture or Knitpicks Gloss DK yarn for excellent pattern definition. Techniques used include Aran cables throughout. The horizontal band is seamless, joined with Kitchener stitch duplicated over waste yarn. After working the crown upwards and the earflaps down, edges are picked up and neatly finished with I-cord edging. A medium size will fit most adults. Written and charted directions are included for extra large size, as well as a smaller size for children. Shown in Gloss DK Cranberry and City Tweed DK Tahitian Pearl, size medium.

Needles:
Size 6 (4.0mm): 16” - 32” circular needle
Size 6 (4.0mm): DPNs