In medium the hat will be longer and can have a larger fold.
In large the hat will have only a short fold as in the photo, but it will become wider than the
medium.
Yarn ASAP from Madelinetosh 100 % Merino wool 82 meters / 112 gram
1 (1) skein
Needles Circular needle 10mm (US 15). 60 cm/24 inches)
Length of hat 30 (25) cm 12 (10) inches.
Gauge on needle 10mm (US 15) in rib pattern: k3, p3: 24 sts = 10 cm / 4 inches.
Make a swatch of 30 sts and work at least 6 cm / 3 inches and measure the center 24 sts.
Remember to check the gauge and adjust needle size accordingly.