I recently purchased an LNB from freeviewshop- a 11-300 band-p-548
I found when it arrived that the diameter was too thick to fit the bracket for the current double thin pronged LNB.
When I notified the store that it was not suitable and asked for instructions to organise a refund I was then sent a link to purchase an additional bracket that increased the total purchase price by 60% with no further instruction. When I replied that I still would like to return the product as it is unsuitable ( I managed to source an old identical second hand LNB to fix the problem) and you cannot tell from the webpage photo or blurb what the dimensions are I got a rather abrupt reply telling me in no uncertain terms that the larger diameter is standard. When I look about at other LNBs in this area many have the same dual design. I don't want to make a big fuss as it was not particularly dear but I do not think I have been treated with courtesy, and I am too inexperienced to know whether the point he makes is valid.