The Scosche FAI4 allows you to connect an aftermarket amplifier to a car stereo which does not have RCA outputs. This allows the four speaker-level inputs to convert to four RCA cable outputs which is ideal for a 4-channel amp. Converts car Stereo speaker wire outputs to RCA cable outputs. Let’s you add 4-channel and 2-channel amplifiers to a factory or aftermarket car stereo. Allows replacement car stereos to be used with most factory amplified systems. Provides adjustments for level matching or fine-tuning your systems volume. Works with high power car stereos up to 80 Watts per channel. Requires aftermarket or factory amplifier which are sold separately. The Scosche FAI4 is backed by Scosche’s Lifetime Tech Support and 1-year .