Shure SLXD14E/SM35 K59, Digital UHF Wireless System, Frequency range: 606 - 650 MHz, With black SM35 headset microphone, Microphone polar pattern: Cardioid, Microphone frequency range: 45 - 20,000 Hz, Peak SPL: 153 dB, 24 Bit / 48 kHz audio transmission, 120 dB dynamic range, 44 MHz switching bandwidth, Switchable transmission power: 1 mW / 10 mW, 12 Compatible channels per 8 MHz band, Frequency transmission via infrared interface, XLR/Jack output, Pocket transmitter with TA4M connection, Transmitter operates on 1.5V AA batteries, optionally also with Li-Ion battery SB903 (not included), 19"" Mounting hardware included