Long Wireless Signal and Adjustable 15 Frequency Channel: ●The microphone adopts UHF frequency band and which provide the long transmission distance (Open Place: UHF distance 168ft/50m, Bluetooth 32ft/10m), low delay and crystal clear sound quality.●If you use multiple microphones at the same time, Click the “CH” button at the end of the microphone to adjust the channel. | Rechargeble Microphone: ●No need to purchase additional AA batteries. ●The microphone and receiver are both built-in 1200 mAh rechargeable lithium-ion battery. work time up to 7 hours with charging time 3-4 hours.●Cool led light ring (working in green,charging in red),and a enhance fashion clear white led display. | Easy to Use:●Plug and play, no need to pair, long press the "PWR·VOL" button to turn on the microphone. Only for input devices with 6.35mm (1/4") or 3.5mm (1/8") MIC port, E.g speaker, Singing machine, audio amplifier, PA system, Voice amplifier, truck speaker system, Dome speaker system etc. ●Receiver with Bluetooth.Turn on the receiver and insert it into your audio device, search for the Bluetooth name: Bietrun, Play your music for karaoke. | Multipurpose Microphone:●Built-in Dynamic Cardioid microphone, Voice is clearer. widely applied to conference,speech, Web podcast, Yoga instructor, church, get together, Family party, Opening Ceremony, dancing instructor, Promotion etc. ●The mic outer case is alloy material which is harder, lighter and more wear-resistant, This microphone has a better weight and grip experience. | 1-Year Warranty:●Bietrun offers 1-year warranty and free replacement service. ●Compatible with ION Speaker/JBL Partybox Series/Sony SRS-XPSeries/Bose S1/PYLE PA System/Electro-Voice ELX Series/PRORECK Club Series/PARTY Series/Rockville BPA Series.