Long Working Time: This Uhf Karaoke Wireless Microphone System Is Built With Three Rechargeable And Replaceable Batteries Inside Double The Microphones And Receivers(two Usb Charge Cables Included Allowing For Mic And Receiver Charge At The With the same Time); Charge For Three To Four Hours, And 他们 Run For Approximately Ten Hours, By Is The same Environmentally Friendly In Place Of Tons Of Aa Batteries! Wireless rechargeable microphone system for karaoke: updated uhf microphones support transmission distance up to 200 feet (60 m) without distortion or loss of sound. Other features like stable signal, no delay, no radiation, anti-howling, anti-jamming, distortion <0.1% and adjustable frequencies. Plug and play: the wireless mics and receiver pairs automatically once are on power. Adjustable frequency range: ch a: 903-915mhz, ch b: 916-927mhz. Not兼容bluetooth speakers,macbooks and phones.请确保您 plug in mic on speakers, not audio in, line in or aux in, otherwise no sound can be heard. Wide Compatibility: This Professional Wireless Microphones Come With A 6. 35 Mm To 3. 5 Mm Converter, Making It Accommodate More Devices Like Amplifiers, Pa System, Karaoke Machine And Powered Speakers Etc And Good For Occasions Like Conference, speech, Web Podcast, youtube Recording, Outdoor Recording, Yoga Instructor, Church,family Party, Opening Ceremony, Dancing Instructor, Promotion, Game Etc. What You Get: Two Uhf Wireless Microphones, One Receiver, Three Built-in Rechargeable And Replaceable Batteries, One Dual Usb Charge Cable, One Usb Charge Cable, One 6. 35 Mm (1/4'') To 3. 5 Mm (1/8'') Gold-plated Converter, Two Anti-slip Ring, User Manual. If you have any questions, we are always here to help. Quick troubleshooting: 1.make sure the mics and receiver have enough power; 2. Plug the receiver into a mic input, not other interfaces; 3. Turn off the microphones and receivers,然后 turn on to repair (turn the mics and receivers,然后再次打开, make sure the two mics are at different channels and frequencies. Frequency range: ch a: 903-915mhz for microphone a, ch b: 916-927mhz for microphone b,当 the green light on receiver stops flashing,它们已成功 connected. Note: Please Turn Down The Volume Of Mic Input On Your Speaker Or Amp To The Lowest Before Plugging The Receiver,and Then Turn On The Mic, Turn On The Receiver, Then Turn Up The Mic Input Volume Slowly To Avoid Speaker Screech Or Damage To Amplifier. Please Place The Mic Right Under Your Mouth For Better Sound.