Highly integrated digital cover delegate unit, features delicate and elegant clamshell design. Adopt Hi-Fi flat-panel loudspeakers for more evenly distribution. Integrate the function of speech and voting. Heart-shaped projection capacitive microphone with two types of indicator lights. With earphone jacks clear sound with a knob to adjust the volume. President unit has the right to approve or reject delegate’s speech apply and president unit is unrestricted by the number of speakers. President unit has the priority to control conference order in full power. Chairman unit can be series-connected anywhere in the circuit. Power supplied by the master controller at 24V safe voltage. With howl inhibition function when microphone is turned on, built-in speaker will automatically turn off to prevent transfusion voice.