Product Highlights: The GR-HL2 is a 2-channel high-level to low-level Adjustable Signal Converter designed for factory or aftermarket radios that do not have dedicated RCA outputs and Remote 12V Turn-On output. The adapter converts high-level signal from the radio's speaker line and converts it into a low level RCA audio signal. This allows you to add an amplifier to your system for higher power output and better sound quality. This converter also creates a turn-on 12V signal for your amplifier that may be missing from your stock factory radio, has a built-in Ground Loop Isolator. All of this in a Small Form Factor Case! Product Features: 4 Channel Input and Output RCA Converter Adjustable Input Signal Sensitivity Built-in 12V Remote Turn-on Output Built-in Ground Loop Isolator Frequency Response: 10Hz - 50kHz Power Supply: 11-15V DC neg. ground Max input: 100W Input impedance: 15K ohms THD: 0.03%