Size guide

Internal diameter(mm) Internal diameter(in) Desired size
15,3 mm 0.60 in 8*
15,9 mm 0.63 in 10
16,5 mm 0.65 in 12
17,1 mm 0.67 in 14
17,8 mm 0.70 in 16
18,4 mm 0.73 in 18*