Professional VHF Wireless SystemQuartz Lock for Drift-Free Operation Four Microphones Included Power On/Standby/Off Switch Audio Mute Circuitry For Quiet Operation Advanced Companding Circuitry AF Signal LED Segment Meter On Each Channel Individual Channel Volume Controls Individual 1/4" Unbalanced Outputs XLR Balanced and 1/4" Unbalanced Mixed Output Operation Range: Up To 240 ft. Battery Life: Approx. 12 Hours Operating Frequency Range: 210-280 MHz Batteries and 1/4" Audio Cables Included 110V/220V Selectable Rack Hardware Included Dimensions: 2.04"H x 19.09"W x 9.44"D