USA / Canada

5

6

7

8

9

10

11

12

British/ Australian

J 1/2

L 1/2

N 1/2

P 1/2

R 1/2

T 1/2

V 1/2

X 1/2

Inside Diameter

15.7mm

16.5mm

17.3mm

18.1mm

19mm

19.8mm

20.6mm

21.4mm