Size
One size to fit 54-58 cm head circumference
Length from brim to top about 20 cm

Needles
3.5 mm circular needle (at least 40 cm long) or dpns, or appropriate size to get gauge

Other
stitch marker, cable needle, tapestry needle for weaving.

Gauge
20 sts and 30 rnds in 10 cm in stockinette stitch with needle 3.5 mm. Take time to check your gauge. Adjust needle size if necessary to obtain the correct gauge.