To fit head circumference:
Baby/Toddler: 15-18 inches
Child: 17-21 inches
Adult: 20-24 inches

Skill required:
Work in the round, either using double-pointed needles or circular needles with magic loop method.

Materials:
Yarn:
Worsted weight wool or wool- blend 50 (60, 75) g
Needles:
4.0 mm (US#6) circular or double-pointed needles
5.0 mm (US#8) circular or double-pointed needles
1 Stitch marker
Tapestry needle

This warm and very stretchy beanie is knitted up with Rickrack rib. The pattern calls for a lot of knit through the back loop and knit through the front loop techniques which can be a little confusing. Picture instructions are attached in the end of this pattern.