Measurements:

Wristwarmers: Approximately 19cm/7.5in in circumference around hand (unstretched), and 20cm/8in in length.

Hat
Small: 40cm/15.75in circumference at brim (stretches to 47cm/18.5in)
Medium: 45cm/17.75in circumference at brim (stretches to 52cm/20.5in)
Large: 50cm/19.5in circumference at brim (stretches to 57cm/22.5in)