Product Name: Bluetooth Digital Amplifier BoardProduct model: XH-A150Chip model: PAM8403Transmission distance: up to 20 meters (no blocking)Supply voltage: 5V (-input)Color: greenmaterial: metalNumber of channels: 2Maximum : 5W+5WProduct net weight: 42gProduct size: 102*69*24mmInstructions for use:1. Install the TR18650 battery first, pay attention to the positive and negative points (Battery is purchased by yourself)2. Two wire link audio speakers, red is positive, black is negative3. Insert an SD card with song files in the SD card slot or a USB flash drive with song files inserted in the USB interface.4. Open the open key, it will automatically read your SD card or USB flash drive, and start playing songs. If the SD card and USB flash drive are installed at the same time, it will read the SD card file and play it by default.Package Contents:1* Amplifier BoardOnly the above package content, other products are not included.Note: Light 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.