It's a partially oddly labelled diplexer due to poor tech English from the Chinese source.
(EDIT: If the Aerial King label is attached its English words are correct and standard, as detailed below.)
Here's the correct usage from Aerial King for normal and reverse (when RF-cabling HB (HeartBeat) distribution needs to be created) diplexer use;
ANT (S1) - connects to the RF In or Out port (depending on user's needs)
I/O (PX) - connects to the LNB's cable coming from the dish
SAT (S2) - connects to the LNB input port
ANT (S1) - connects to the RF coaxial cable you will be routing
I/O (PX) - connects to the LNB input port
SAT (S2) - connects to the LNB's cable coming from the dish
Photo attached for those able to view it properly.
If you have problems call C.J. at Aerial King: 082 558 8797
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