Item Type: Voice AmplifierMaterial: PlasticColor: BlackBattery: 1 x 18650 Lithium Battery (Shipped with Built in Battery) (2200mah)Memory Card Slot: Without Memory CardUse: Teacher Teaching, Shopping Mall Promotion Waist Hung Speaker PlayerPackage List1 x Charging Cable 1 x Voice Amplifier1 x Headset Microphone1 x Waistband1 x Instruction Manual 1Multiple Applications: The voice amplifier is compact and portable for presentations, meetings, teaching and other outdoor activities. 2Clear And Stable Sound: With premium 3 inch speaker, it has powerful sound amplification effect, the sound is clear, stable and not easily deformed. 3Input Method: Mini voice amplifier supports a variety of sound input mode, can be inserted U disk, Memory Card, adapt to different sound input needs. 4Long Battery Life: The waistband amplifier has a built in 2200mah battery, which can be used for up to 10 days on a single charge. 5Multi Function: This portable voice amplifier can also be used for class replay, with headset microphone, which is very wide range of use.