This cowl is available in two sizes:

Small: Circumference: 24½“, Height: 7½”
Large: Circumference: 46”, Height: 11”

The size is further customizable and how to do so is described in the pattern

Yarn Requirements

Large Cowl: Dyed in the Wool by Spincycle Yarns (54g/200 yds, 100% superwash wool)
Color A: Nostalgia, 2 skeins
Color B: Devilish Grin, 2 skeins

Small Cowl:
Shibui Knits Birch (50g/262 yds, 100% extrafine merino wool )
Color A: Abyss, 1 skein
Color B: Ivory, 1 skein

While this cowl is designed to be made with sportweight wool, you could conceivably use any weight of wool. You can easily adjust the size of the cowl to accomodate a wide range of gauges.

The instructions are written out but the plaid pattern motif is charted only. This is a relatively simple design that would be good for a colorwork beginner.