【Wireless microphone system with echo/treble/bass】:● The wireless karaoke microphone set has echo, treble, bass control button, you can use different sound effects according to different songs. ●The system has bluetooth, connect via bluetooth( bietrun) to play your favorite music.●The wireless mics have 30 channels, each 15. Remove the battery cover of the mic, short press the grey circle button to adjust channel to avoid interference. For karaoke, speech, meeting, conference, indoor, outdoor. [Professional UHF Wireless Karaoke Microphone System] The microphones adopt fcc certified UHF frequency band, which provide the long transmission distance (Open Place: UHF distance 98ft/30m, Bluetooth 32ft/10m).●Frequency Response 50Hz-16kHz●Signal stability ●No delay ●No radiation ●Anti-howling ●Anti-jamming ●Constant frequency ●distortion <0.2%●Clearer sound quality.※※※Not compatible Bluetooth speakers※※※.Can Only Plug in mic jack, no plug in Aux jack, otherwise no sound can be heard. 【portable and professional dual dynamic microphone】: plug and play, no extra setting. ​You can adjust echo, treble, bass, volume or switch channels on the handheld microphone at will, portable and convenient, eliminating the trouble of carrying the receiving system. comes with dual handheld wireless karaoke microphone, widely applied to conference, speech, web podcast, yoga instructor, church, get together, family party, opening ceremony, dancing instructor, promotion etc. 【1200mah battery and display】：the receiver of this wireless microphone set built-in 1200 mah rechargeable lithium-ion batteries can offer about 8 hours working time and fully charged in 3 hours. the microphone does not come with any batteries, we recommend using 2 aa amazon alkaline batteries. and our bluetooth microphone has large led display, you can clearly to see the batteries, channels and signal. 【Advanced connection and after sales】: If your microphone has no sound, make sure you have enough power for the microphone and receiver. insert the mic jack, not an aux/line in jack. bietrun offers 1 year warranty and free replacement service.can write to us when you have any questions.we will be the greatest brand in the united states.

1. Use UHF technology, give you clearer sound quality, signal stability, no delay, anti-howling, anti-jamming. 2. Working range : UHF up to 160 ft, Bluetooth range is 10 m 3. Operate all function on the handhold microphone 4. Bluetooth 4.2 available, search the Bluetooth "Bietrun 08" in the Bluetooth device list and connect it. 5. 15 sets working together: 30 microphones max 6. High quality sound : ECHO, reverberation regulation 10 Levels TREBLE , high pitch adjustment, 8 Levels BASS, Bass adjust, 8 Levels 7. Volume Adjustable: 5 levels total 8. High Quality Material: alloy casing, steel meshed microphone head 9. Large LCD Display: power, signal, frequency, channel statues display