Converts high level audio signal to RCA format, Line OUT adapter (converter) to 2 RCA (pre-amp), for the 4 channel amplifier you need 2 converters The hi-low adapter allows you to connect a car radio to an amplifier, even if the radio does not have an RCA output. This improves the performance and sound of your car radio 2 channel outputs, separately adjustable, voltage converter, gold-plated RCA contacts, galvanic separation, for 2 channels also for subwoofers or kick-bass Installation of the adapter is very simple. Simply connect the radio speaker cables to the adapter inputs and then connect the adapter RCA cables to the amplifier inputs 2 channels or outputs adjustable separately in the level. - Frequency 20 - 22,000 Hz - High power input up to 2 x 50 W - Dimensions: 90 x 63 x 22 mm (L x W x H)