This pair of Sennheiser Half-Wave Antennas are designed for use with EW-D EM receivers or EW-D ASA antenna splitters in the 470 to 550 MHz range. They are equipped with swivel BNC connectors for flexible positioning. These 1/2-wave antennas dramatically improve the performance of your EW-D EM receivers or antenna splitters. They are an upgrade from your standard 1/4-wave antennas that are included with most receivers.