The Sennheiser AC 41-EU (article 508243) is an active antenna combiner for Evolution Wireless in-ear monitoring systems. It lets up to four SR IEM G4 (or other ew-series) stereo transmitters share one transmit antenna, which cuts antenna clutter at the side of stage, reduces intermodulation compared with several antennas close together, and makes larger IEM rigs neater to set up. The combiner also powers the connected transmitters over their BNC antenna cables from its own NT 3-1 power supply, which is included, so separate transmitter power supplies are not needed. It covers 470 - 870 MHz, spanning the common UHF ranges, and draws a maximum of 3.4 A with transmitters connected. This EU version ships with the EU-plug power supply but without a rack mount kit, so a separate 19-inch rack adapter is needed for rack installation. It is aimed at touring bands, churches and hire companies running multiple wireless monitor mixes. Antennas and BNC cables are not included.