The Betas58A with the SLX2 transmitter features the Beta 58A supercardioid dynamic microphone head which gives you superior sound quality and is tailored for lead and backing vocals. It also provides maximum isolation from other onstage sounds. The SLX2 Wireless Handheld Transmitter includes a timed backlit LCD display, frequency and power lockout and "Mute" functionality. This transmitter requires the SLX4 receiver to complete the system. All Shure wireless transmitter designs allow for interchangeable microphone heads.