Size guide

Size Guide.

UK size US size Inside diameter (mm) Inside circumference (mm)
A 1/2 12.04 37.8
B 1 12.45 39.1
C 1 - 1/2 12.85 37.8
D 2 12.04 40.4
E 2 - 1/2 13.26 41.7
F 3 13.67 42.9
G 3 - 1/2 14.07 44.2
H 4 14.48 45.5