1.Aluminium  board with black brushed treatment.
   2.It has check-ins, votes, ratings, and video tracking functions.
   3.The airline connector, can split the microphone and make the voice  clear.
   4.It use the long service life and no noise of touch swith.
   5.The connection location of chairman unit is free.and it can be connected  to any location.
   6.The unit has equipped with the2M,8P aluminum and 3M shielding wire.
   7.The speaking model:FIFO/LIMIT/FREE/CHAIRMAN.