Dell Precision 5560 External Display Connection Manual page 8

You can connect up to three external displays directly to the Type-C ports on your computer or you can connect the displays to
the computer using the docking station.
● Connect three external displays directly to the two Type-C ports and the docking station:
● Connect up to four external displays directly to the WD19TB series docking station and than connecting the docking station
to the computer:
8 Connect external displays