This pair of Sennheiser HALF WAVE DIPOLE 1/2-wave antenna rods are designed for use with EW-D EM receivers, Evolution Wireless Digital or the EW-D ASA antenna splitter. Offered as an upgrade from the 1/4-wave antennas that come with the receivers, they provide added range and reliability for your mic wireless system. Each antenna rod is equipped with a swivel BNC connector. This version is for the  606-694MHz frequency band.