Written in US Terms.
Skill level - advanced beginner/intermediate
Knowing the bases of knitting on circular needles, joining in the round, gauge, and being able to read basic knit terminology will be key.
There is an abbreviations chart.
Gauge and what yarn I used is included.
Materials list and finished dimensions.
Link to youtube tutorial for main stitch used.

Sizing:
Fits average adult head. Also great for teens, and easily adjustable for younger kids.