Features: 1. With two AUX and Bluetooth audio input methods, 2 in 1. 2. The potentiometer adjusts the volume through the switch, which can easily control the volume, which is very suitable for DIY speakers. 3. When using a filter inductor, the sound is round and clear. 4. It uses copper direct current connector and fence terminal. It can withstand high current, no heat, no damage to cable, good wiring and short circuit. 5. Free direct current head cable, compatible with the input power interface of this product, even if you don't have a direct current head adapter or battery, you can easily connect. 6. 5.0 Bluetooth version, the transmission efficiency is greater, the transmission distance is longer. Notice: 1. Actual color may be slightly different from the image due to different monitor and light effect. Please allow minor deviation due to manual measurement. 2. Objects may have Logo, if you want to know, please contact us. Otherwise, please do not bid. Specification: Type: HIFI 2.0 Stereo Bluetooth Digital Power Amplifier Board Chip solution: TPA3116D2 with AM interference suppression With or without filter: Yes filtered sound is more round and clear Applicable the power supply voltage: DC5-24V optional 9V/12V/15V/18V/24V adapter, high power recommended high voltage is not suitable for 24V battery power supply, otherwise the voltage will be too high damage Adapter speaker: 30W200W, 4ohm, 8ohm Number of channels: left and right stereo stereo Bluetooth version: 5.0 Bluetooth transmission distance: 15 meters without occlusion Protection mechanism: undervoltage, overheating, DCdetection, short circuit protection Tip: To have enough output power if the audio input is sufficient and the supply voltage/current is sufficient. The power supply voltage is higher and the relative power will be larger. The speakers with different impedances will have different output power. In the case of sufficient voltage and current, the larger the ohms of the horn, the smaller the relative sound power. Please pay attention voltage: 12V-8 European speaker / 12W left channel 12W right channel, 4 ohm speaker / 20W 20W 15V-8 ohms / 18 18W, 4 ohms / greater than 30 30W 19V-8 ohms / 32 32W, 4 ohms greater than 45 45W 24V-8 ohms / 38 38W, 4 ohms / greater than 55 55W Size: 82x50x18mm Package List: 1 set x Digital Power Amplifier Board/ 1 x Digital Power Amplifier Board with case