Brand new and high quality Features: Stereo sound, it has wide frequency response, high efficiency, low distortion, and low noise, the sound effect is good. Designed with a volume potentiometer, you can easily raise and lower the voice. With reverse connection for power supply for protection, short circuit for protection, and overheating for protection. Wide supply voltage and two audio input modes, more efficient. Specification: Material: PCB circuit board Size: app.55 x 38 x 18cm/21.65 x 14.96 x 7.09in Color: As the picture shows Quantity: 1 Pc Product Parameters: Product Model: XY-P40W Supply Voltage: DC: 8~24V Bluetooth-compatible version 5.0 Connection distance: 15 meters (visible) Output mode: Stereo Output power: 20W x 2 @12V 4Ω 30W x 2 @16V 4Ω 30W x 2 @21V 8Ω 40W x 2 @24V 8Ω Speaker selected (40W~200W): 4Ω (5-16V power supply) 8Ω (5-24V power supply) Instructions: 1. After connecting the power supply, the blue LED will light up, and it will enter Bluetooth-compatible mode, waiting for pairing after playing Beep; 2. Turn on your phone's Bluetooth, "XY-P40W" will be searched and displayed; Click "XY-P40W", it will connect to the board. It will connect successfully with a beep; 3. After this, you can play music. The amplifier board will prepare for the next pairing with a beep. Caution: 1. Keep a safe distance from the router to avoid WIFI interference 2. 5-24VDC is recommended; higher than 26V, it will be damaged. 3. When driving 4Ω load, the power supply must be under 16V; and when driving 8Ω load, the power supply must be under 24V. 4. The supply current must be at least 2A. 5. The line connecting the speaker to the module should be within one meter. 6. ESD for protection, please discharge ESD on your hands before contacting the module. 7. 40W and higher power speakers are recommended. Note: No retail package. Please allow 0-1cm error due to manual measurement. please make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the item's actual color. Thank you! Package includes: 1 x Bluetooth-compatible amplifier board 1 x User Manual