Shure P9RA+ Features: Advanced digital signal processing technology yields incredible headroom, stereo separation, and audio fidelity Precision front-end RF filtering reduces RF interference for a stronger RF signal, fewer dropouts, and fewer artifacts CueMode allows monitoring of different stage mixes and storing of up to 20 separate channels for quick and easy reference Scan and Sync scans your RF environment and wirelessly assigns a group and channel to your system MixMode technology combines two separate audio channels for simultaneous listening in both ears 4-band parametric EQ for achieving a fully customized sound Input EQ Presets for tailing your sound further Match setting allows you to duplicate the sound of the P9RA Advanced rechargeability options.