Specifications:Built-in 2200mAh battery can be used for 10 days.Portable voice amplifier is designed with large volume and clear sound, and there is no noise.It is suitable for teaching, tour guides, parties, lectures, promotions, training, etc.It is compatible with devices with 3.5mm auxiliary port as speaker.Item Name: Audio SpeakerMaterial: ABSWorking Voltage: DC 3.7VCharging Voltage: DC 5.0VDisplay: LED DisplayBattery: Built-in 2200mAh Battery (Included)One-key Recording: with One-key Recording Function (When recording, you need to insert a TF memory card or U disk.)External Storage Play: Support U Disk/TF Memory Card Player (MP3 Format)Amplification Function: Support Plug-in MicrophoneFM Radio: Support FM RadioFunction Mode: "M" Function Key Support Switch to FM or MP3 PlayerFeatures: with Microphone, Teaching Accessory, WiredSize: 11.7cm x 8.5cm x 3.9cm/4.61" x 3.5" x 1.54" (Approx.)Notes:Due to the light and screen setting difference, the item&39;s color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement.Package Includes:1 x Audio Speaker1 x User Manual1 x USB Cable1 x Wired Microphone1 x Belt