1. Eliminate the humming noise caused by grounding in some car speakers/home stereos. 2. Without an external power supply, this noise isolator can achieve clear voice/music by eliminating noise in some car speakers/home audio systems. 3. It is suitable for any portable device with a 3.5mm jack for your home stereo equipment. 4. Moreover, it is lightweight and doesn't take up much space, and can be picked up. 5. Project type: 6. Interface: 3.5mm 7. Frequency response: 20HZ - 20KHZ 8. Input: Stereo 9. Dimensions: 59 x 20 x 18 mm 10. Material: Plastic 11. Color: Black 12. Package contents: 13. 2 x Ground loop noise isolators 14. Only the above package contents are included, and no other products are included. 15. Note: Due to light reflection, the product color in different screenshots may vary slightly from the actual product. The measurement error is +/- 1 - 3 cm.