1. Parts Selection: Two audio are used, and the transformer material is from aerospace materials. 2. High sensitivity and high reduction, 10-20DB higher sensitivity than similar low-end , full tone, quality. 3. Line design: stereo two-channel design, circuit board specifications: 45MM X 30MM, very small, suitable for small cars and other interior installations. 4. Connection : Two connection methods, which can be input and output through a 3.5MM headphone jack, or can be directly wired through two blue wiring jacks. 5. Main function: Eliminate current sound. A common ground-isolated audio transformer eliminates current noise from the AUX common ground. The output and output ground lines are isolated by the transformer and there is no common ground. Descriptions: 1.This is a an audio common ground isolator module. 2.It is effective for the noise caused by the common ground for the audio source and the receiving device. Specification: Name:Audio common ground isolator Colour:As shown Material:PCB Size:55x30x20mm Package Contents: 1 x Audio Stereo Isolator Only the above package content, other products are not included. Note: Light 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.