Opella Push Button.
I have an Opella system installed in my toilet cistern, over the years I have had to replace these button valves many times, either the button on the top breaks or the bottom of the valve splits, I could get these from B&Q normally but they have discontinued stocking them. I am glad that I've found a stockist that keeps these and am sure (as long as they remain in stock) will continue to buy replacements as and when needed. I usually keep a spare for when they break and replace my stock.
ps. If I'd known the issues I've experienced with these units I would not have bought a system with these parts. This my personal experience and other users may not have had the same type of issues.
Verified purchase: YesCondition: New