Remove . Eliminate the noise caused by ground when the audio source and (some car speakers/home audio systems) use the same power supply, so as to achieve clear music enjoyment, and the best will bloom from there. quality. There is no damage of rock music, a better experience, and can be used on mono. Easy to use, just plug and play, no battery required. Small and portable, this gadget doesn't take up much space and is easy to take . Works with any portable device that has 3.5mm audio jacks, for your Car Audio System/Home Stereo. This product can only eliminate noise and current noise caused by common power and common ground products, but cannot eliminate noise caused by other reasons, so you need to confirm of the noise yourself. Specification: Size Chart: 75x37x21mm/2.95x1.46x0.83inch Color: Black Material: ABS Package Contents: 1 x Audio Noise Filter Only 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.