Wireless handheld microphone with built-in transmitter offers 16 UHF channels so your presentation will go smoothly. All wireless devices of any type are subject to interference caused whenever a receiver can "hear" more than one transmitter broadcasting on the same frequency. This "jamming" effect can sound like a howl or squeal distortion of the mic signal or even no sound at all coming from the receiver. UHF frequencies are less susceptible to environmental noise. This transmitter gives you 16 channels from which to choose with a frequency range from 584 MHz to 602.45 MHz. Use only with Amplivox Executive Sound Column Presidential Plus or Elite lectern SW models.