With patented Audio Reference Companding, exceptional transmitter linearity, and patented CueMode functionality, the Shure PSM® 900 Wireless Personal Monitor System meets the needs of professional audio applications of all kinds, providing excellent audio quality and reliable RF performance. Twenty compatible frequencies per band and a 36 MHz to 40 MHz tuning bandwidth give the PSM 900 system the horsepower to handle demanding environments, including professional IEM and IFB applications.