Which dual-flush WC flush valve do you recommend?

[Chapelgirl]

I have just replaced the fill valve in my close-coupled WC and it is now clear I need to replace the flush valve as well. The cistern is just short of 30cm tall to the lip, but the main issue with it is that the hole in the top of the lid that takes the push-button is only 20mm across, and where suppliers give dimensions for the button at all, they all seem to be bigger than this.

Can anybody point me in the direction of the right fitting, and one that is of a decent make?

Thanks in advance.

 

[blup]

You could buy one/some from Screwfix and see what fits, they have an excellent returns policy.

Blup

 

[blup]

I'm no expert but in my experience, Fluidmaster and Thomas Dudley are good.

Blup