Frequency Adjustable: This wireless microphone system features dual UHF technology with a selectable frequency range of 520 MHz to 580 MHz; Smooth and quick IR synchronization; Long range operation of 200 feet to 250 feet Anti-interference Feature: Wireless karaoke microphone equips with auto scan function, which can search for the least interference channel to pair up with transmitters; 2 antennas design increases anti-interference ability each channel Easy to Use, Plug and Play: Plug the receiver into the MIC jack only , but not into the AUX jack, then turn on the wireless microphone systems, the receiver will automatically synchronize its frequency with the karaoke microphones Independent Volume Control: Each dynamic mic features its own volume control so you can balance the vocals as desired for a karaoke experience that both kids and adults will enjoy. Perfect for PA, karaoke, party, church, meeting, wedding, speech, DJ Packing List: 1 pc wireless receiver, 2 pcs UHF wirele