If it is used in a car (12V voltage), please use the car lighter power supply. Connecting to the car battery 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 be burned out.If it is for household use, please use a 12V 2A power adapter.Amplifier type: hifi power amplifierSize: 155x85x45mm/6.1inx3.3inx1.7inRated voltage: 12VRMS power: 40W+40WMax power: 400W+400WRated frequency: 20-20KHzResolution: 47KDistortion rate: 0.1SNR: 90dBImpedance: 4-16 Power amplifier type: hifi amplifierInterface type: clipReceiving mode; audio inputWeight: 0.35 (kg)Mini HIFI digital bluetooth audio power amplifier.Aluminum alloy body, , the body is made of aluminum alloy once, the anode 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: BlackMaterial: MetalPackage Contents:1 amplifier1 x Remote control1 x Connector Cable1 AdapterOnly 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.