I am looking at getting the gerberit wall hanging frame and it's somewhat confusing because they have so many different variations. I am looking at the UP320 and it seems it comes in Sigma and Delta. From what I think i understand is that the delta and sigma are two different types of cisterns. Is that right? Is the frame the same? If it's just the cisterns that are different, then what is the main difference? I am looking to get a flush plate like this following link, is this only compatible with the Sigma and not the delta? https://www.amazon.co.uk/Geberit-115-770-Sigma01-Plastic-RAL9005/dp/B008ET4VJ0
