BUILT FOR LIVE: The dual wireless karaoke microphone for adults with the 48kHz/24Bit UHF digital circuitry transmits encrypted signals to avoid signal crosstalk and deliver accurate sound. 15 UHF tunable frequency groups for the micrófono inalámbrico in 902 - 928MHz fend against crowded spectrum conditions, available for simultaneous multiset hookup. The cardioid dynamic singing microphone delivers delay-free stable performance and noise-free pure sound, suitable for live performance. GOOD TO GO: The mini receiver of the karaoke machine has a long-lasting 1500mAh rechargeable battery via USB Type-C. The handhelds are not rechargeable and require AA batteries. For convenient and smooth performance, the autotune microphone features a one-tap frequency selection and a transmitter mute function. Just turn on the UHF wireless microphone karaoke system, and you are good to go with the 160 - 200ft line-of-sight range. Please keep the antenna upward and avoid metal/glass for a better rang