Details5W 2400mAh Voice Amplifier Multifunctional Portable Personal Voice Speaker with Microphone Display for Teachers SpeechDetails - GOOD HELPER FOR YOU - Amplify your sound in crowded occasions. This voice amplifier can provide 5w clear and soft sound to cover about 1000 square meters; let everyone hear what you say.HIGH SOUND QUALITY - Surround 3D sound field; provides high sound reproduction and clearer sound quality; make your voice clear and soft; and will not produce harsh noises.SMALL A