Zoweetek Portable Voice Amplifier with FM Radio Wireless Microphone Headset for Teachers, Tour Guide, Coaches, Training, Presentation (Black) Equiped with dedicated FM wireless microphone headset, wireless connection distance is up to 10 meters (33ft). Easy to pair. No delay and no disconnection. The sound is clear, crisp, no noise and no distortion. The max 5 watts sound can cover about 5000 sq.ft (500 ), suitable for group of 25-75 people. Built in 1500mAh rechargeable lithium battery. Music-play time up to 10 hours, amplification-use time up to 15 hours. You can use mini USB cable to charge it. Supporting TF card playing & USB flash drive playing, this device can loop all music and switch songs. It also can be used as a FM radio. 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. Very portable.