Measurements
To fit average head size
56 cm (22 inches)

The given length of yarn is for the whole beret set:
Beret, Fingerless Gloves and Double Moss Stitch Scarf.

Each pamphlet has a different set of recommended yarns. The following are from the Studley version.

Materials
For full set
Beret, Fingerless Gloves and Scarf
STUDLEY Double Knitting
Five-in-One
M 2 balls
C 1 ball
Five-in-One Royal
M 2 balls
C 1 ball
Five-in-One Fashion
M 2 balls
C 1 ball.