Reminder : Only the receiver has bluetooth function, microphones doesn't have bluetooth. About this item PLUG AND PLAY: With a mini portable receiver that comes with 1/4 output, this wireless microphone system is easy to set up with your powered PA speaker, mixer or amplifier. Microphones can be automatically paired with the receiver when turned on and are hassle free ECHO/TREBLE/BASS EFFECTS: You can easily adjust echo, treble or bass to the desired level with the buttons on the mics; perfect for karaoke, meeting, speech, wedding, church and etc; The cardioid pick-up pattern emphasizes main sound source and minimizes background noises. Better yet, the handheld microphones are rechargeable and come with rugged metal housing and stand heavy use INTERFERENCE FREE: The Ultra-High Frequency (UHF) microphone system minimizes radio frequency interference and noises generated by other electronic equipment and digital devices. It provides cordless freedom, ease of use and 50 selectable UHF frequencies (10 frequencies per microphone, 500-599 MHz) for interference free operation FULL COMPATIBILITY: The SZKOSTON microphone receiver comes with 1/4" (6.35mm) output and is compatible with most PA speakers, mixers and amplifiers which come with 1/4" input connectors. The system has an operation range of up to 200 feet RECHARGEABLE HANDHELD MICROPHONES: Easily recharge your microphones with a USB charging cable and say goodbye to the hassle of removing and inserting batteries. Simply plug, charge, and go