Size guide

Our sizes

US & CAN

 Inside diameter UK & AUS FRA DE JP CH
5 15.7 MM (0.618") J 1/2 - 15 3/4 9 -
6 16.51 MM (0.65") M 52 3/4 16 1/2 12 12 3/4
7 17.35 MM (0.683") O 55 1/4 17 1/4 14 15 1/4
8 18.19 MM (0.716") Q 57 3/4 18 16 17 3/4
9 18.89 MM (0.748") R 3/4 - 19 18 -
10 19.84 MM (0.781") T 1/2 - 20 20 -