Description: 【High Level to Low Level Signal Conversion】: This Wire Adapter for Car Stereo efficiently converts high level speaker signals into low level RCA outputs, making it ideal for connecting car amplifiers or subwoofers to audio systems without RCA outputs 【Built in Relay for Amplifier Activation】: The Radio Converter Adapter equipped with a built in relay, the device powers on your amplifier by utilizing a 12V voltage from the amplifier's power side when the car's audio system sends sound signals 【Wide Compatibility】: The Car Radio Stereo Wiring Harness is ideal for head units without low frequency (RCA) output, such as cassette players, CD players, VCD/DVD players, and more 【Details】: Made of plastic material with a compact size of 2.17inchx1.38inchx0.79inch, ensuring easy installation and long term performance 【High Signal to Noise Ratio and Separation】: Delivers good sound quality with minimal interference due to its high signal to noise ratio and good signal separation capabilities Size Chart: 5.5cmx3.5cmx2cm/2.17inchx1.38inchx0.79inch Package Includes: 1 Wire Adapter for Car Stereo  Note: Please allow slightly errors 1-2cm/0.39-0.79inch differences due to manual measurement.