The ECD series is a dual channel wireless system. The ECD features 2 internal antennas (1 for each receiver), 16 selectable channels on each receiver and IR Sync from receiver to transmitter. The ECD has one 1/4-inch output on the back of the unit. The output is controlled by a volume control for each receiver, located on the front of the unit. It includes ECDR receiver, MBP38 bodypack transmitter and LV13-UBK lavalier microphone.