[Small but very powerful] -- If you want to buy a personal voice amplifier that is small and lightweight, then the S17 is for you. It is a portable microphone speaker with 30 watts of output power, which can greatly enhance your voice and protect your vocal cords, so you can easily make your voice heard by 25 to 100 people. [ Single battery life] -- The small voice amplifier comes with a 2200mAh high-capacity lithium battery that provides up to 12 hours of operation on a fully charged battery. Charging is easy with the included USB cable. And it only takes 3-5 hours to fully charge. [Convenient and Portable] -- The portable speaker comes with an adjustable strap that you can tie around your waist or hang around your neck. The teacher amplifier has a clip on the back, you can attach it to a belt or waistband. The wired headset microphone is adjustable. [Stable Performance] -- It is an original voice amplifier with stable performance. The portable headset microphone is a flexible gooseneck design that is placed just close to your mouth. Perfect for anyone doing events that need to project their voice. Suitable for teaching, trainer, singer, coach, guide, shopping mall, presentation, yoga, outdoor speech, etc. Size: 8.4 x 9.2 x 2.8 cm