From booklet:

Instructions are for size Small. Changes for Medium and Large are in parentheses.

MATERIALS - Sport Yarn Weight

SPINNERIN Sabrina (50-g) 2 A (Orange), 1 (2-2) B (Yellow)
OR Elf 4 A, 2(3-4) B
Round elastic

CROCHET HOOK: “Boye or Diana” Size F OR SIZE TO GIVE GAUGE

GAUGE: 6 sts = 1 inch
5 rows = 1 inch