Supatap washer: is this a type A, B or D?

[fishtail]

First thanks for the advice on how to undo a supatap (my earlier thread)

. Now it’s undone I’m not sure which washer I need.

Online you can buy Type A , B and D supatap washers but the photos all look the same. My old one is 1/2” diameter with a jumper stem 3/8” long (see photo). Anyone know whether this means it is an A, B or D?

 

[pigletrunning]

Measure the diameter - size A is 12.5 to 13mm, size B is 20-21mm, there is another size of 15-16mm which I suppose is size D. Sizes A and D are for 1/2" basin taps I think (two designs). Size B is for 3/4" bath taps. I don't know anything about size C or if it even exists. Hope this helps.