Cable TV, Antenna, Coaxial - what is this thing?
It's an antenna / satellite combiner. Appears to be an aftermarket add-on.



It takes both LNB feeds from the dish, along with the antenna signal, and combines them onto one wire. In this case, it looks like it fed four boxes. Apparently this unit could combine them without a splitter on TV end.

Either way, I wouldn't use it without a satellite dish. A regular signal splitter would suffice.