Small in size but powerful in function - if you want to buy a small and lightweight personal voice amplifier, then the S17 is your best choice. It is a portable microphone speakerWith a 30 watt output power, it can clearly amplify your voice, protect your vocal cords, and make your voice easily heard by 25 to 100 people.Long battery life - This small voice amplifier is equipped with a high-capacity 2200mAh rechargeable lithium-ion battery, which can run for up to 12 hours when fully charged. Charging through the included USB cable is very simple. Fully charging only takes 3-5 hours.Comfortable and portable - The portable speaker comes with an adjustable strap that you can tie around your waist or hang around your neck. There is a clip on the back of the teacher speaker amplifier that you can clip onto your belt or waistband. The wired headphone microphone is adjustable.Stable Performance - This is an original voice amplifier with stable performance. The portable earphone microphone is a flexible gooseneck design that can be placed directly at the mouth. Very suitable for people who hold events and need to speak up. Suitable for teaching, coaching, singers, coaches, tour guides, shopping malls, public speaking, yoga, outdoor speeches, etc. Size 8.4 * 9.2 * 2.8CM