Green Lion 2 In 1 Wireless Microphone With 70mAh Battery Transport Distance Barrier 20m-30m No adapter or Bluetooth is needed, you can just plug in and play. The 36 hours of playtime are solely designed for your convenience to use the wireless microphone at your own pace and time. The accurate voice-picking feature is another special feature this device is famous for. Owing thanks to the 64 DBM adaptive noise reduction now you can listen to your favorite music without any excessive noise. Noise reduction. Wireless transmission. The input voltage is 5V. The frequency response range is 20-20kHz. Transport distance barrier 20m-30m. The battery capacity is 70 mAh. Accurate Voice Picking DSP Noise Reduction Plug To Use Comes with Charging Box