Keeping your Subaru factory radio and adding something in between the radio and the car? This combined harness will save you time and effort. All 20 pins are already connected straight through. All four speaker channels (8 wires) are longer, ready for you to cut in the middles and connect to your speaker amplifier, Line Output Converter (LOC), or other aftermarket gear.
The ground and two +12V power wires already have "T" branches connected. Use the Red +12V Accessory line for an amplifier remote turn-on (since most Subaru factory radios don't have that signal).
Wires have the EIA-standard color-coding used by after-market head units and other equipment, with text labels (for example, "Left Front Speaker +").
All 20 pins have wires. For models with CAN data bus (2008-up Impreza and 2009-up Forester), the two CAN bus wires are tightly twisted to preserve signal integrity.