2.1 Channel 2x300W Bluetooth Digital Power Amplifier Subwoofer Hi-Fi MP3 Stereo Enhancer Home Bass Audio Player Class D -When using in the car (12V voltage), please use the power supply of the cigarette lighter in the car. The battery lead connected to the automatic tool may generate noise. -When used on a truck (24V voltage), it can only be used when the voltage is reduced to 12V with a roller coaster. Otherwise, the power amplifier will be burnt. -Please use 12V 2A power supply for household use. professional: -Subwoofer Hi-Fi stereo Bluetooth 2.1 channel amplifier. -Lightweight aluminum housing, the surface of the machine has been brushed and oxidized. -Red ring plug-in inductor + large capacitor filter. -With sockets that can be inserted into MP3, MP4, iPod or CD players. -With treble, bass and volume control, it is very easy to use. -Low distortion ensures clearer, stronger, and more powerful sound. -Adjust the high frequency and low frequency separately to find the frequency band you want. -Very suitable for use in your car or home. Clean up: -Product Name: HiFi Power Amplifier -Material: Aluminum alloy -Fab: Silver -Bluetooth: 5.0 -Span: 12V 3A -Maximum power: 2*300W -Signal to noise ratio: 80dB -Impedance: 4-8 -Error rate: 0.01% -Rated frequency: 20Hz-20KHz -Interface type: Clip -Receiving method: audio input -Size: 15.4 * 12.9 * 3.9cm / 6.1 x 5.1 x 1.5 inches Included packages and will: Type 1 -1 x hi-fi amplifier (without power supply) -1 x User Manual Type 2 -1 x 12V2AB battery Type 3 -1 x Hi-Fi amplifier -1 x User Manual -1 x 12V2AB battery