Features: ER-202 is equipped with exclusive high-quality stereo in-ear headphones to make the sound more realistic. The wireless ear-monitor system is used in stage performance and sound broadcast which can replace traditional complex sound monitoring equipment, achieve admirable listening effect. The advanced circuit design, high quality IC chip , clear most the receiving blind angle to make the system's receiving signal steady. LCD display shows clear working status. Specification: Unit Size of the Transmitter: 420*110*43mm; Unit Size of the Bodypack Receiver: 95*65mm; Modulation Method: π/4-DQPSK; Frequency Range: 510-580 MHz,2x100 Selectable frequency point; Sampling Ratio: 48KHz; Transmission Rate: 204.8Kbps; Dynamic Range: ＞90dB; Total Harmonic Distortion: ＜0.1%; Delay Time of Audio Transmission: ＜3ms; S/N Ratio:＞96dB; Frequency Response: 30～20Khz; RX Sensitivity: ＜-94dBm; Unique ID Address: YES. Some tips to improve the performance of the system: 1. The transmitted and antenna should kept in the relative position of accessibility of the straight line. 2. Don't put the receiver close to the radio wave emission source, with magnetic objects or most digital devices (such as the CD player, computer, speaker, wifi etc). 3. Try to place the receiver in height of 1.5 meters from the ground and the position of a distance of 1 meter away from the wall.