The HB series HT-3000 Conference main unit is designed to support 60 delegate delegate and chairman chairman units and it can also be extended extended to support 200 microphone unit with use of extension power supply. It has built-in monitor speaker and its system can support 1/2/3/5 free modes. It is equipped with four groups of 8P-DIN Interface for system connection. HT-3000 Conference can support video cameras auto tracking when it is connected with video processor HT-8008. The HT-3000 main unit is designed in accordance to ISO and IEC914 standards.