★ Every conference main unit can drive up to 60 units, and can drive over 200 units by adding expansion main unit.
★ The system has the function of limiting the quantity of delegate unit, can choose the limit address type directly , such as"1", "2", "3", "5"or "all open".  When choose "1" or "2" or "3" or "4" or "5", the delegate unit which opened at the same time can not excess the quantity choose, when reach the choose quantity, besides the delegate unit is turned off or the president unit press the button, or else the new delegate unit can not be opened; when choosing “1”, it can answer before others. There is no limitation for the chairman unit and it can open at any time.
★ Built-in the telephone coupler, it can open a telephone conference with remote user
★ Internal feedback restraint circuitry; set up alt/ bourdon digital adjust circuitry, so as to adjust system’s timbre independently; also can adjust the sound;
★ Equipped with balance circuitry output interface, left/right circuitry output interface, unbalance output interface, so as to adapt the connection of each kind of equipments.
★ 110V-240V AC Power ( can produce according to the requirement of different countries) 50/60MHz   power:115W