DCS-103B is a power supply expander for the DCS-101C and DCS-102D Mic stations of the Digital Conference System DCS-100. It is used when more than 16 Mic stations are necessary in the system. One DCS-1003B boosts up to 32 additional MIC stations (16 per line 1 & 2). For 72 Mic stations (max), 2 x DCS-103B devices are necessary.