The Shure MX890-G4 Wireless Desktop Base features a built-in wireless transmitter that is compatible with Shure's G4 series wireless microphone receivers. The boundary microphone features a cardioid polar pattern for sufficient noise suppression and optimum pick-up of conversations, speech, interviews, etc. The internal wireless transmitter eliminates the need to run cable and drill holes. A programmable Mute switch includes push-to-talk and push-to-mute modes. Bi-color LED provides status information and the MX890 is conveniently powered by two AA alkaline batteries.