Toilet Syphon Tail Washer

[DiyNutJob]

Do the toilet syphon tails come in different sizes? I need a new set of rubber washers and couldn't work out the size I should buy. The O.D. on the threaded tail is 47.5mm. So the I.D. of the washer needs to be this size. I can see these at toolstation. Any of these is right for what I need? Thanks.

I am unable to attach an image. Have I been banned to do that, or there is a problem with the forum?

Syphon Tail Washer

www.toolstation.com

1 1/2" to 2" Adaptor Seal

www.toolstation.com

Syphon Tail Washer

www.toolstation.com

 

[DiyNutJob]

Never mind . Found this on ebay "Approx 45mm inside diameter, fits over a 1-1/2 inch male BSP thread." So, I have 1-1/2 inch male BSP thread. I still don't understand how 1.5 inch BSP becomes 47.5mm.