Which are suitable for the item can be listed as follow?
1.The car audio or amp whines when the engine is running.
2.The audio or amp noise issue was caused by a ground loop.
3.The noise of vehicles power and charging system.
4.The engine noise made by aftermarket stereos of amps.

How to know whether the item were useful for your car?

If your car was already install the car amplifier or car subwoofer and it had noise when your car engine running, you need the item.

If the engine is running your car amplifier or audio have whines, but has no noise when the engine is off, you need the item.

If it has noise coming into your stereo from your vehicles power and charging system, you need the item.

If the amp or audio has no noise when not plugged into power or the engine was not running, and your alternator or ignition is sending noise through the power. You need the item.

Feature:

It can eliminate ground loop noise between audio source and the amplifier (audio).

The male plugs for input wires, female plugs for output wires.

Usage Method:

Open your car panel, find out the head unit and amplifier (audio).

Connect two male plugs to the main output wires of the head unit.

Connect two female plugs to the input wires of the amplifier (audio).

Finish it, start the car alternator, the noise will be released even be eliminated.

Note:

When used with car audio, this isolation circuit goes between the head unit and the amplifier or audio.

Please check the situation of your car. If the item can't reduce or eliminate the noise for your car, maybe your car is not the situation listed above.

Specifications:
Material:Plastic & Metal
Current:20A
Voltage:12V
Input Power:30W
Max Input Power: 60W
Frequency Range:20-30KHz
Package include:1*Mr. Ho 20A Car Audio Noise Suppressor