This pattern including both size M with DK weight yarn and size L with Fingering weight yarn.

YARN
Size M: Shangdrok DK Merino (100% Super-fine Merino Super Wash - 225m / 100g) 1 skein, color Red / Beaver / The Orchid Thief
Or approximately 160m of DK weight yarn
Size L: Shangdrok Wool Donegal (65% Wool 30% Nylon 5% Linen - 400m / 100g) 1 skein, color The Orchid Thief / Aubergine
Or approximately 200m of Fingering weight yarn

NEEDLE
3mm / 3.5mm / 4mm circular needle with 80cm cable or longer for magic loop technique.
(or Double Pointed Needles)
Adjust needle size if necessary to obtain the correct gauge.

GAUGE
Size M: 22 sts x 28 rows = 10 cm in 2 x 2 rib stitch on 4mm needles after blocking.
Size L: 23 sts x 34 rows = 10 cm in 2 x 2 rib stitch on 3.5mm needles after blocking.

FINISHED MEASUREMENTS
Size M: W 12cm / H 29cm, to fit head circumference 50-56cm.
Size L: W 13cm / H 32cm to fit head circumference 56-60cm.