... Group calling, Brief Introduction of the queue calling systemThis Calling System is mainly used in fast food restaurant, cantee,clinic, ... of customers waiting for his or her service. They system consist of a transmitter (Numerical Keypad)for the caller ... the open areaWorking temperature-20C-80CStore temperature-40C-80CCase materialPC case (black, white, blue, red)Standard accessoriesone main unit, ...