The SL Mic Hub 1 ist connected to the TeamConnect Combox CB1 via a 6-pin terminal connector cable. The Combox delivers the necessary power supply to operate the bi-color status LEDs of the mute button MAS 1 TC and the hook button MAS 2 TC. The Combox supplies sufficient power for up to 5 MAS 1/2 buttons. If you want to use more than 5 buttons in your setup, you need to connect an external power supply (5 V, >100 mA, recommended Sennheiser Power supply Art.-No. 534480) to pin 6 and 7 of the MUTE socket.