Mpow Ground Loop Noise Isolator for Car Audio/Home Stereo System with 3.5mm Audio Cable (Black) ELIMINATING BUZZING NOISE : Completely eliminating the buzzing noise, caused by ground loops which happens when the audio source and the speaker use the same power source in some car speakers / home stereo systems when using the Bluetooth receiver. WORKING PRINCIPLE : The working principle of this noise isolator is to achieve a clear speech/music by eliminating the current noise in some car speakers / home stereo systems. COMPATIBLE MODELS : Works with any portable device that has 3.5mm audio jacks, for your Car Audio System/Home Stereo, when grounding issues persist. Also used with a Bluetooth Receiver/Bluetooth Hands-free Car Kit in your Car Audio System/Home Stereo. COMPACT AND PORTABLE : Being so mini and light-weight (2.01*0.59*0.59 IN, 0.99 OZ), this little gadget does not take much space and can be easily taken away. NOTE: The Ground Loop Isolator connect to the AUX Jack in car to eliminate noise.You will enjoy good quality sound when use it with Ground Loop Noise isolator.