Shure BLX14/P31 T11, UHF Wireless System, PG Headset Series, BLX1 Pocket transmitter, PGA31 Headset microphone, Up to 3 systems simultaneously, Pilot tone, Microprocessor-controlled antenna diversity, Quick-Scan function for free frequency detection, Condenser Headset PGA31: 60 - 20,000 Hz, cardioid, Plastic receiver, Integrated antennae, XLR and jack outputs, Audio status LEDs, Frequency range: T11 (863-865 MHz)