Your "Power Divider" does not split Horizontal and Vertical polarizations, it prevents other tuners to send power to the LNB, so that only 1 tuner can control the LNB, wich is not the right way to do things.
Since you obviously already bought the TBS 6985, you should also buy a QUAD LNB, wich has 4 outputs that go to the 4 INPUTS of your TBS 6985.
The difference with a QUAD vs QUATTRO is that a QUAD is essentially the same has having 4 dishes pointed at the same satellite, a QUATTRO outputs the 4 polarizations seperate on each output and should be used in combination with a multiswitch for GSO installations.
But do not use that "Power Divider" if you have no idea what it does.