**********The ultra-high frequency (UHF) microphone system minimizes radio frequency interference and noises generated by other electronic equipment and digital devices. *****Easy to set up and operate with preset dual-channel UHF frequencies and independent volume controls ( 540.9 MHz and 581.4 MHz). frequencies are Compliant with the Federal communication commission rules*****Up to 200 feet operation range with stellar quality. Ideal for conferences, Broadcasting, weddings, Karaoke, social events and medium-sized venues such as meeting rooms, schools, churches. *****Audio compressing-expanding technology can minimize noise and boost dynamic range. The Cardioid microphone pickup pattern produces superb feedback and off-axis rejection*****IMPORTANT! Please contact us at Customer Service to get an additional 12-month warranty or if you are experiencing any connectivity issues.