The Sennheiser A 2003-UHF Wide-Band Directional Antenna enhances transmission and reception for wireless microphone and monitoring systems; such as the Sennheiser SR 300, SR 3054, SR 3056, IEM transmitters, Evolution wireless, 3000 and 5000 series wireless, and the EM-1031U monitoring system.. It has a frequency range of 450-960 MHz, an apex angle of approximately 100 degrees and a front-to-back ratio = 14 dB.