Multifunctional Microphone amplifier:Supports TF (Micro SD) card playing, USB flash drive playing and 3.5mm AUX audio input (Mic port can be used as AUX port). You can repeat single tune, loop all music and switch songs. Flexible design:You can adjust the distance between your mouth and the mic to fit your purpose. The voice amplifier uses ABS material with high light technology, durable and wear-resistant. Portable voice amplifier:This amplifier is very Lightweight and portable. You can use the back clip to fix it on your belt or pocket. You can also use waistbelt to tie it around your waist or hang it on your neck. Rechargeable voice amplifier:Built-in 1800mAh Lithium battery,amplifying time is up to 12 hours. Music playing time is up to 10 hours. Only need 3~5 hours to be fully charged. Voice amplifier for teachers:This voice amplifier saves your voice from yelling or shouting out.Loud voice, no distortion.A perfect voice aid for who have difficulty speaking or have a low voice .