This product is a portable personal voice amplifier worn on the waist. Power: Maximum sound output reaches 8 watts. Battery: It has a built-in rechargeable lithium battery, providing a long playback time of up to 12 hours. Features: Lightweight, comes with a wired headset microphone, and supports playing MP3 files via memory cards (TF) or flash drives. Usage: Ideal for teachers, tour guides, and trainers to amplify their voice without straining their vocal cords.