Shure BLX2/SM58 Handheld Wireless Microphone Transmitter | Frequency: H11 (572-596 MHz)Made for musicians and public speakers, the BLX2 SM58 from Shure is a handheld wireless transmitter that's ideal for singing and speaking applications. It's particularly useful for occasions where multiple people need to be miked for short periods of time, or when you need one mic source for multiple people, such as in a Q&A session. Transmitter comes with two AA batteries and a mic clip.