Needles: Fingering weight ribbing: US 1.5 (2.5mm) 16 inch needle
Fingering weight body: US 3 (x mm) 16 inch needle and dpn or 32 inch for magic loop to decrease
Fingering blocked gauge: 7 stitches/inch, 10 rows/inch

DK weight ribbing: US 3 (mm) 16 inch needle
DK weight body: US 5 (x mm) 16 inch needle and dpn or 32 inch for magic loop to decrease
DK blocked gauge: 6 stitches/inch, 9 rows/inch

Notions: Tapestry Needle, 4 stitch markers

 
This hat can be knit in a single color, or a contrast color can be used for a cool effect with the slipped stitches. I will label the rows for the contrast color (CC), but this is completely optional 

Fingering weight stitch counts and sizes (based on stated gauge)
136 stitches (19.25 inches), 144 stitches (20.5 inches), 152 stitches (21.75 inches)

DK weight stitch counts and sizes (based on stated gauge) DK has a little less stretch
120 stitches (20 inches), 128 stitches (21.33 inches), 136 stitches (22.66 inches)