The S278 is a personal voice amplifier designed to reduce vocal strain and amplify the softest voice.This portable microphone is excellent for large rooms, at its max it will allow the speaker to be heard in nearly 10,000 square feet of space with clear sound and no distortion. This headset microphone with speaker device is light weight, easy to use and portable. Conveniently straps around your waist, or slings over the shoulder. Take it with you wherever you go. 2500 mAh Lithium battery can be easily charged with the help of included USB cable and lasts for sufficiently long hours. It is a portable microphone headset with speaker which is ideal for a teacher, public speaker, exercise instructor or an individual with chronic low volume. Specifications: Power output: 15 W, Battery capacity: 2500mAh, Charging: DC 5V, 500mA, Charging time: 3-4 hours, Working time: Speaker:8-12 hours(mic mode), 6-8 hours(music mode) Size: 4.5 x 3.5 x 1.3 in, Weight: 0.44lb What's in the package: 1 * voice amplifier, 1 * wired headset mic, 1 * USB charging cable, 1 * AUX cable, 1 * waistband, 1 * user manual