The sound of S358 microphone amplifier is clear, crisp, no noise and no distortion.It has double power, the 4000mAh battery provides 38 hours keep using. This mini voice speaker is charging with type-C port.Portable loudspeaker comes with an adjustable band that you can use it to tie around your waist or hang on your neck. Teacher speaker amplifier has a clip on the back, you can clip on a belt or the pant waistband. The wired headset microphone is adjustable.Fashionable design that is suitable for teaching, trainer, singer, coach, tour guide, shopping mall, presentation, Yoga, outdoor speech and etc.This speaker amplifier can work as an MP3 audio player, can be used on computers and mobile phones.