Geberit concealed flush panel identification and opening

[bluecoffee]

I'm trying to identify which Geberit flush panel this is:

I think it is an Omega 20?

If this is the case, I think I'm supposed to open it by pulling the right edge towards me, then sliding the whole thing left as per these instructions. But I don't want to break it, and it's not opening up.

Is this the correct panel, and if so, do I apply more force? Or is it a Sigma 20, in which case I should push the lower edge down, then pull the top edge out towards me?

(The large left button is often getting stuck in, causing water to flush continuously, hence the desire to have a look inside).

Many thanks

 

[dilalio]

You push it to the left or right (there's a spring that allows you to do this) and then you lift it away from the wall at the opposite end of whichever way it pushes.

Same with up and down (I think)

But you slide them first then lift opposite side.

 

[dilalio]

https://www.google.com/search?q=rem...id-ee-uk-revc&sourceid=chrome-mobile&ie=UTF-8