Toilet Siphon Query

[stender]

Hi All,
I'm having to change my toilet siphon as the membrane has split but I have a query on the replacement part.

It's a small close coupled cistern and takes a smaller than average siphon.
I have seen lots of 8inch, 10 inch siphons at places like screwfix but not any smaller ones. My question is what is the 8 inch or 10 inch measurement? is it the part where the membrane is?
My siphon measures just under 5 inches by just over 3 inches on the square part but total length is around 7 inches.
It says Jetflow on the top which is green and is in an ideal standard cistern.

Also any idea on the cheapest place for a replacement? I've not found the exact one but seeing some for upto £30 whereas the standard size in screwfix is just over a fiver!

thanks in advance

 

[seco services]

The height ie 8" etc is measured from the base to the overflow on the syphon.

Try ideal standard fast part.

 

[stender]

aah ok thanks. But the height is not the concern, its the size of the diaphram part as it hits the fill pipe if too large. The standard size from screwfix fits hiegth wise but too big at bottom.
so if they only give height mesaurement i'm going to struggle buying anything except the exact same make one.

 

[Newboy]

why not just replace the membrane?

 

[Charnwood]

Replace with a Fluidmaster flapper valve.
http://www.screwfix.com/p/fluidmaster-toilet-flush-valve-conversion-kit/38533#