Size X-Small 6-1/2 – 6-5/8 Inches 20 1/2 – 20 3/4 52-53 CM
Size Small/Medium 6-3/4 7-1/8 Inches 21 1/8 – 22 1/4 54-57 CM
Size Large/X-Large 7-1/4 – 7-5/8 Inches 22 5/8 – 23 7/8 58-61 CM
Size XX-Large 7-3/4 – 7-7/8 Inches 24 1/4 – 24 5/8 62-63 CM