Latest Enhanced Amplifier voice amplifier uses the developed noise reduction technology, anti-interference, anti-howling, no noise. Makeing your voice clearer, sensitivity and more penetration without distortion. Amplifies your voice without calling out loudly. Rechargeable Voice SpeakerThis mini voice amplifier supports continuously amplify up to 16 hours or 14 hours of music playing, Only 2.5 hours need to fully charge it. Suitable for teachers, trainer, singer, coacher, tour guide, shopping mall, presentation, outdoor speech and etc. Adjustable Headset MicrophoneWith the flexible gooseneck design, the portable voice amplifier speaker with microphone headset can be adjusted to a suitable position to the mouth. The graceful curve and humanized construction makes this microphone headset fit the head perfectly, stable and comfortable. Compact and Portable K700 Plus portable microphone and speaker with compact size (4.3 x 3 x 1.1 inches, similar size to a smart phone) and lightweight (0.38 pounds). Easy to be fixed on the waist band or pocket with the back clip, hanged on the shoulder or waist with the included 1.5 meters(59 inch) belt. Worry-Free After-Sales ServiceFrom 30 Years of Professional Audio Manufacturers, Every product of the Portable Voice Amplifier has passed strict industry quality testing standards, and keeps dedicated to protecting your precious voice and conveying your beautiful voice. Gifts for teachers classroom Specifications.120x90x35mm.Model.T92.4G wireless version.Frequency response range.1 (Hz).Distortion rate.1 ( percent ).Output power.15 (W)