Imperial System:

 Size A (in) B (in) C (in)
XS 21 ⅞ 3 ⅛ 2 ¾
S/M 23 ⅜ 3 ½ 2 ¾
L/XL 25 4 2 ¾


 

Metric System: 

 Size A (cm) B (cm) C (cm)
XS 55.5 8 7
S/M 59.5 9 7
L/XL 63.5 10 7