Usage Tips:Features: 1. Support reading MP3 music in U disk and TF card 2. Built-in Bluetooth receiving function, can receive Bluetooth music from mobile phones; 3. For 7.4V lithium battery, can be charged with DC9V/1-3A charger; 4. With AUX IN external audio input function, can be connected to the computer to play; 5. The panel has a wired jack, which can be used to sing or sing; Using word power amplifier, rated power 15W, peak 30W; Description: It must connect a 7.4V battery to open.- -this is very important for power on. The positive and negative poles of the battery must be connected according to the this picture, otherwise the board will be burnt. NOTE: (VERY IMPORTANT!!!) Material: plastic colour: black Package Contents: 1 x Bluetooth Amplifier Board 1 x Remote Control(randomly style. Cannot be chosen the specific style.) 1 x Cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-YJL official store