?BONAOK Rechargeable Battery?— 2600mAh rechargeable multi-protect lithium battery(18650) ensures a longer sing time. Quicker charging, long-time lasting. ?EASY TO USE?— Multi-function buttons, easy to switch to different model, adjust volume, sing and play music. With echo model,our karaoke wireless microphone can bring a surrounding immersion. And the USB port allows you to plug USB, turn this magic piece to MP3, and play it directly. ?HIGH COMPATIBILITY?— Supporting micro SD card max 32GB(NOT INCLUDED) and song switch. The Bluetooth has a great distance of connection(10m). ?TWO WAYS CONNECTION?— Bluetooth Connection & Cable Connection. You just need to connect your phone with cable or Bluetooth, and then open the singing APP on your phone. The built-in clearly audio and vividly sound effect can make you listening and singing anytime and anywhere. ? PARTICULAR DESIGN? - The excellent design of our karaoke wireless microphone is very suitable for your hand, which can make you feel more comfortable. And the built-in high-quality Bluetooth module can be used as speaker, player and Recorder, compatible with various singing applications.