It has four seperate outputs so it can be used for any Sky or Freesat receiver. One Sky Plus or Sky HD receivers plus 0ne or two standard Sky or Freesat boxes (3-4 outputs). Up to four standard Sky or Freesat receivers (1 - 4 outputs).
Yes I know that. I also know he was asking about changing it for the Sky+ type.
My point was based on the fact that as this thread is
A. not in the Sky section of the forum, and
B. the fact that the OP intends to use a Freesat box (most of which use the Sky+ type LNB), BUT if he is considering the Arris Freesat box, there is an advantage in not changing the LNB.
The LNB you linked to is required if the OP is not considering the Arris box.
There you go. Post justified, with reasoning.