XIRIUM PRO Receiver RX Base Station, including NXPA-6-360-25, NXPA-WIFI, NKXPRO-DATA, NXUC-M-15. The repeater is the perfect extension of the system: When used, the system range can be doubled, and walls, corners, or other obstacles may be overcome. Since the repeater duplicates and forwards the signals received from the transmitter it becomes a second, redundant audio source for every receiver. Each receiver automatically selects the best signal and switches between them without interruption.