Description of 2.1 channel power amplifier board: 1. The remote control, U disk and AUX terminals were connected to the power amplifier board Bluetooth power amplifier. The right plug-ins must be inserted and the functions can be adapted to the work. You can't solder the line yourself, and there is a risk of burning the Bluetooth chip.2. Power & Power Supply: Regulated Switching Power Supply: Up to 20V; Maximum power supply 12V 2*15 + 30W 4Omega; power supply 20V maximum power 2*25 + 50W 8Omega; Product Name: 2.1 Channel Amplifier with Subwoofer Board Supply Voltage: 12-20V DCamp Power Supply: 3-5A Maximum Power: 2*25W+50W 8Omega; Minimum power: 2*15W + 30W 4-8Omega; Bluetooth Version: 5.0Channel: 2.1Working Type: Class D Product Size: 96x48mmColor: BlueMaterial: PCB + Metal Package Contents:1 x Bluetooth Power Amplifier Board1 x AUX Audio CableOnly the above package content, other products are not included. Note: The light and different displays may cause the color of the item in the picture to be slightly different from the real thing. The allowed measurement error is +/- 1-3cm.