XVIVE U4 Wireless In-Ear Monitor System - One Transmitter Four ReceiverOne transmitter and four receiver. 2. 4GHz wireless in ear monitor system create your personal or band monitor system. Solid RF connection over a 90 feet range(actual range depends on RF signal absorption, reflection and interference) Up to 107 dB signal to noise ratio provides clear, detailed audio at any volume. High Resolution 24 bit 48kbps audio. Broad 20Hz 20KHz frequency response. Dynamic Rang 107 dB. Less than 5ms Latency, Simultaneous