Sizing Chart

 Diameter

US

UK

14 mm

3

f1/2

14.6 mm

3.75

h

15.3 mm

4.5

h1/2 - i1/2

16 mm

5

j - k

16.5 mm

6

l - l1/2

17.2 mm

7

m1/2 - n1/2

17.8 mm

7.5

o - p

18.5 mm

8.5

p1/2 - q1/2

19 mm

9

r1/2 - s

19.8 mm

10

t1/2