The TS-919B1 and TS-919B4 are bridge units for connecting the TS-911, TS-912, TS-811, and TS-812 wired conference units to the TS-910 Central unit. The Bridge units are directly connected to the TS-918 expansion unit connected to the central unit. A single conference unit can be connected to the TS-919B1 and up to 4 conference units to the TS-919B4. Connection between each bridge unit and the expansion unit or conference unit is made with a single CAT-5 LAN cable.