If it is used in a car (12V voltage), please use the car cigarette lighter power supply. Connecting to the car battery will cause noise. If it is used in a truck (24V voltage), you need to use a step-down device to reduce the voltage to 12V before it can be used. Otherwise, the power amplifier will be burned out. If it is for household use, please use a 12V 2A power adapter. Amplifier type: hifi power amplifier Size: 155x85x45mm/6.1inx3.3inx1.7in Rated voltage: 12V RMS power: 40W+40W Max power: 400W+400W Rated frequency: 20-20KHz Resolution: 47K Distortion rate: 0.1 SNR: 90dB Impedance: 4-16 Ω Power amplifier type: hifi amplifier Interface type: clip Receiving mode; audio input Weight: 0.35 (kg) Mini HIFI digital bluetooth audio power amplifier. Aluminum alloy body, durable, the body is made of aluminum alloy once, the anode surface treatment, the overall atmospheres, thick, feel is also very good. for SD Card, U disk, AUX input, MP3 format play, support bluetooth wireless connection. Supports FM stereo radio. Low distortion supplies a clearer, stronger and more powerful sound. With Remote control function. Plug Type:EU Plug,it applies to Indonesia, Germany, France, Spain, Italy and so on. Voltage: AC220V (with 12V 5A adapter) Color: Black Material: Metal Package Contents: 1 x Power amplifier 1 x Remote control 1 x Connector Cable 1 x Power Adapter