This is my uderstanding . If it is a LNB , a polorotor is normally used in the feed horn to change polarity . The picture seems to show a flange fro a LNB .
A LNBF uses 13 / 18 VDC to change the polarity , but do not know of one that fits that flange . The LNBF's I have seen are complete units that fit a scalar ring . And slide in & out the scalar ring to adjust f/d .
If there is a way to get both polarities on that feed , it might be with what I have read of a stacked LNB . But , some one that knows more , what a stacked LNB is , will have to help you .
I have seen pictures of Ku LNBF's that use the C 120 flange .