The PA411 from Shure is a wideband antenna combiner that distributes DC power and RF signal for up to four Shure PSM300 transmitters (sold separately). It features a compact half-rack system that is used to reduce the amount of antennas and power supplies needed when using multiple systems in application such as for live stage, theater, rehearsals, and more. It features a RF LED indicator display to signal the presence of a signal and a signal overload. It is built with a front panel power switch. Included are rack-ears, 1/4 wave antenna, BNC bulkhead adapter, BNC cable and power supply.