I've recently replaced our two toilets with the type that flush with a press of a central button on top of the cistern.
The first was fine but the second came with a diaphragm in the inlet system that had a small split in it. When I went back to B&Q for a spare they had none and so they had to take one from a complete, boxed toilet.
On that basis it looks like it might be a good idea to keep a spare 'in stock'. Trouble is, I can't find anywhere that sells them.
Anyone any ideas (and what is their correct name)?