Small 51cm circumference, 17cm from top to bottom.
Medium 56cm circumference, 20cm from top to bottom.

Needles:
Small hat 5.5mm (uk 5, us 9) straight needles, 5.0mm (uk 6,
us 8) and 6.0mm (uk 4, us 10) dpns or circular needle.
Medium hat 6.5mm (uk 3, us 10 ½) straight needles, 6.0mm
(uk 4, us 10) and 7.0mm (uk 2) dpns or circular needle.

Other:
Tapestry needle.
Cable needle.