1. 220W+220W+350W, 2.1 Channel Bluetooth Power Amplifier Module, Aux/Bluetooth/U Disk/Sound Card. 2. Bluetooth Connection Allows You To Play As You Wish, Upgraded To Bluetooth 5.1 Version, The Effective Distance Is About 10 Meters, You Can Connect And Play. 3. Simple Appearance, High-Definition Sound Quality, High Fidelity. 4. Easily Connect Your Audio System. Only Level Of Amplification Can The Output Of Sufficient Power. Six Low-Noise Preamplifiers 5532 Improve The Sound Quality And Volume, With Large Gain And A Gain Parameter Of 30db. 5. Protection Mechanism:Anti-Reverse Connection, Under-Voltage, Overheating, Over-Current, Short-Circuit Protection (Can Automatically Recover Without Restarting) Product Name:2.1 Channel Bluetooth Audio Amplifier Module Product Model:-AS21 Number Of Channels:2.1 Channels (Left Channel + Right Channel + Subwoofer) Input :Aux+Bluetooth+U Disk+USB Sound Card (Wheel Button Switches Modes And Songs) Adaptable Power Supply:DC16-38V, equal 10A Suitable For Loudspeakers:Left And Right Channels 30-220W, 3-8ohm; Subwoofer 30-350W 2-8ohm Output Power:Left And Right Channels less than equal 220W; Subwoofer Switch Mode: Mechanical Switch (No Need To Press And Wait) Tip:Only When The Audio Signal Input Is Large Enough And The Power Supply Voltage/Current Is Large Enough, Will There Be Sufficient Output Power! The Higher The Power Supply Voltage, The Greater The Output Power, And The Smaller The Speaker Impedance, The Greater The Output Power! Please Make Sure That The Power Of The Adapted Power Supply Is The Actual Working Power Of The Amplifier! Note:The picture is a high-resolution rendering. Different Batches May Have Differences In Product Appearance, Color, And Printed Characters, Which Will Not Affect The Use. Colour:As Shown Material:PCB Size:About 141x131x27mm Package Contents: 1 * Amplifier Motherboard 2 * Cover Plate 4 * Copper Pillar 8 * Screw 4 * Nut 5 * Knob 1 * Screwdriver 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.