Distribution hub for DCP Wall Controllers that features 9x RJ-45 ports for use with multiple DCP controllers.  
Yamaha Pro RS485 Control Hub for DCP Wall Control Panels
Distribution hub for DCP Wall Controllers that features 9x RJ-45 ports for use with multiple DCP controllers (DCP1V4S-US), (DCP4S-US), and (DCP4V4S-US).
Find additional information like application diagrams and product details on the Yamaha website.