This twin LNB holder can be installed to your existing dish and permit reception of 2 satellites.  The LNB's are connected together via a 2 way DiSEqC switch (NOT INCLUDED) and your original cable now connects to the switch instead of the dish.  Once your decoder has been configured in the Antenna Settings menu, it will automatically switch between channels from either satellite.  Common satellite combinations are Optus C1/D2, Optus D2/D1, Optus C1/Intelsat8, Optus D1/Intelsat8.  Minimum recommended dish size is 85cm.