The Shure PA411 Antenna Combiner distributes DC power and RF signal for up to four Shure PSM300 transmitters. The compact half-rack system significantly reduces the amount of antennas and power supplies needed when using multiple systems. Antenna combiner distributes DC power and RF signal for up to 4 PSM300 transmitters. The compact half-rack system reduces the number of antennas and power supplies needed when using multiple systems.