Features: GOOD HELPER FOR YOU: Amplifying your sound on busy occasion. This voice amplifier can provide clear and smoothing sound to cover in the classroom, let everyone hear what you are saying. HIGH SOUND QUALITY: 3D surround sound field, provides high sound reproduction and clearer sound quality, makes your voice clear and smoothing and does not produce loud-noise. SMALL AND PORTABLE: The size is only 9.2x8.4x2.8cm, compact and lightweight, it won't carry too much burden. Comes with an adjustables strap and clip, allows you to wear it at the waist or hangs it from the neck. MUSIC PLAYER FUNCTION: Supports USB flash-drive playback and TF card playback, you can repeat a single melodys, loopingall music and switch songs / record content, you will never missing any important information again! WIDE USE:Ideal for teachers, tour-guides, physical trainers and anyone who needs to improve their sound. For classrooms, conferences, speeches, trainings, meetings, shopping centers, etc. Notice: 1.Actual color may be slightly different from the image due to different light effect 2.Please allow 1-3cm deviation due to manual measurement Size: 9.2*8.4*2.8cm Battery capacity: 2200 mAh Package List: 1 Set Portable Amplified-Speaker for Teachers