[GROUND LOOP NOISE ISOLATOR] Eliminates noise interference that may occur when the audio source is connected to the playback device and no signal loss. Plugged this audio noise filter up and it instantly took the buzz/hum/static out of your car audio system/radio/home stereo/speakers. Give back the clear music to you. [Plug Play] Extremely simple operation. Plugged this ground loop isolator directly into the cars/speakers AUX port, then the aux cable into the audio source. You will see the change was instant Completely solved the noise problem This noise filter does not require charging and has no built-in battery. [Wide Compatibility] ground loop noise isolator works with any device that has a 3.5mm jack including cell phone, laptops, tablets, computer, mp3 players, or other speakers. You can also combine it with a Bluetooth adapter in your car audio system/home stereo system. [Lightweight Portable]This isolator is made of new polymer materials to achieve high strength, wear resistance, light weight, etc(2.4 * 0.75 * 0.75 in, 0.05 lb). Its diameter is only half of 25 cents. The gadget is easy for you to carry.