Size	Length (A)	Width (B)
XS	17 ⅜ in (44 cm)	18 ¾ in (47.5 cm)
S	17 ¾ in (45 cm)	19 ¾ in (50 cm)
M	18 ¼ in (46.5 cm)	20 ⅝ in (52.5 cm)
L	18 ¾ in (47.5 cm)	21 ⅝ in (55 cm)
XL	19 ⅛ in (48.5 cm)	22 ⅝ in (57.5 cm)