The Sennheiser AWM UHF Antenna is an active directional antenna for use with Evolution Wireless Digital microphone systems. The AWM UHF antenna is designed to enhance the wireless performance of your Evolution Wireless Digital system and can be installed quickly and easily in any room, on a vertical (wall) or horizontal (ceiling) surface. The AWM UHF can be connected to any stationary Evolution Wireless Digital receiver or EW-D ASA antenna splitter.