Toilet flush siphon (new) (Dawlish)

A dual flush siphon - Internals for a toilet cistern. It's dual flush and made by Opella. It's never been used and is in its packaging with all the instructions. The packet had a little rip so I have taken everything out to check it (to my untrained eye I think it's all there) one foam ring thing is squashed (see photo) and would need replacing. As you can tell I am not a plumber, so I cannot advise on its suitability, but I hope it can be useful to someone!