Shop name:Chong Qing Shuo Yue Ke Ji You Xian Gong Si Eliminating Buzzing Noise caused by ground in some car speakers / home stereo . No external power supply, this noise isolator can achieve a clear speech/music by eliminating the current noise in some car speakers / home stereo . Works with any portable device has 3.5mm audio jacks, for your Car /Home Stereo. Compact and lightweight, it will not take much space and can be easily taken . Item type: Audio Interface: 3.5mm Frequency response: 20HZ-20KHZ Audio input: stereo Colour:As Shown Material:plastic Package Contents: 1 x Audio frequency common ground isolator Only the above package content, other are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.