Video of RWM81U: How To Set Up Your RWM81U: What's in the Box: 2 wireless headset microphones 1 receiver unit 2 1/4” Guitar cables User manual Batteries Power adapter Features: Rockville RWM81U Dual Wireless UHF Headset Microphone System High performance wireless headset microphone system Includes transmitter with two high sensitivity, unidirectional, wireless, cardioid headset microphones Featuring a dual filter design to limit feedback and interference Ultra signal stability eliminates unwanted distortion Professional receiver with multifunction color displays shows frequency, signal synch, and audio input Transmitter automatically links to receiver for ease of use Use any two mics (handheld or headset) at once Individual microphone volume controls Rugged metal housing Comfortable ergonomic composite microphone construction Low power consumption for longer battery life System: Operating Range: 300'– 400'(indoor), 250' – 350'(outdoor) Channel: Two Channel Frequency Range: 560.10 - 577.60 MHz Frequency Stability: ±0.005% Modulation Mode: UHF Frequency Response: 50Hz - 15KHz (±3 dB) Dynamic Range: 105dB S/N: 100dB T.H.D: 0.5% (1KHz) Audio Output Jack: XLR balanced & amp; 1/4" mixed Power Supply: 110V Operating Temperature: 3°F - 130°F Mic Battery Operating Time: up to 10 hours Oscillation mode: Quartz Crystal RF Output Power: 10mW Output Level: 0 – 300mV Dimension: 9.05" x 6.69" x 1.96" Weight: 2.95 lbs