Bodypack Transmitter operates exclusively with AmpliVox 16-channel UHF systems, and will not work with other manufacturers wireless receivers. Flesh Tone single over-ear/headset electret condenser unidirectional mic with 16 Channel UHF wireless bodypack transmitter (S1690T). Frequencies: 584 to 608 MHz. Requires two "AA" batteries (included). (Replaces S1635).