ZOWEETEK Original voice amplifier-- HiFi original sound amplification! 1.High power ultra light inner trumpet, low weight, voice is strong and clear, also very wide coverage. 2.Original voice amplifier: Very long operating time --- up to 15 hours clear & loud amplification with a single fully charged. 3.Sound covers 5,300 sq ft– powerful waistband voice amplifier delivers amazing sound & excellent clarity; amplifies your voice across larger Auditoriums. 4.UHF wireless amplifier, with 40m/130ft wireless transmission technology, no need to carry the device any more, completely hands-free, more convenient and comfortable. 5.Widely used: teaching, tour guide, yoga, lectures, meetings, karaoke, fans singing, morning exercise, dance, training and so on purpose Features: Output power: 10wCharging Voltage: DC 5v, 500mA Material: ABS Product Size: 106 mm 86 mm 42 mm(3.4x1.1x4.2inch) Unit Weight: 163g Musical use time: 8--10 hours Amplification of using time: 12-15 hours Charging time: 3 hours Package: 1 X S615 wireless voice amplifier 1 X Adjustable waistband 1 X Wired microphone 1 X Wireless microphone1 X USB charging cable 1 X US plug wall charger1 X manual Note: 1.The microphone can not be close to other microphones or speakers as this will produce coupling and generate a reverberation that never ends when a microphone is near a loudspeaker will catch the sound of it and emit a shrill voice and create a loop up Cut off the current or move away from each other. 2.Turn on the mini amplifiers and then press "M" Button until you see the blink blue light and then let go;Turn on the wireless microphone and then press the signal button 3S on the microphone and it will pair successfully. (Generally, it will automatically hook up the next time you use it.).