Nady EO3 BB Wireless In-ear Monitor System Ultra compact and lightweight; antenna integrated with earphone cord Preset to one of eight channels in the 72-76 MHz range Loudness adjustable with volume control-provides up to 120dB in-ear monitoring One pair of mini binaural EB-3 earphones included; optional EMI soft rubber inserts supplied 5. LED Power On indicator and requires one 9V alkaline battery for operation