This PAC pre-amp converter (also called a differential converter, line output converter or high-low converter) is used to convert the speaker output from your factory car stereo to low level. This will allow you to add an aftermarket amplifier to power additional speakers or subwoofers. It can be hooked up in stereo or mono mode.
On one end, you'll splice it into your factory speaker wiring. On the other end is a converter box with RCA output jacks. You'll use an RCA 'patch' cable to connect it to your aftermarket amplifier. It alos includes a 12v remote turn-on wire so it only powers up if the key is turned on.
This is for all factory car stereo systems with 60w per channel or less. If you have a premium sound system with an amplifier, you will need to know the output per channel of the amp. If it is higher than 60w per channel, this needs installed in the wiring going to the amp, not the wiring coming out of it.
This is not a normal stock item but is usually shipped directly to you from the manufacturer to avoid delays.