Reasonable and neat power plug, it has the prefect bonding and contact stability. Provide clean and excellent sound. Easy to install. Use this adapter when adding an amplifier to a factory radio that convert the radio's speaker level output to the lower amplifier (RCA) level input. Tap into a speaker wire and it senses the signal, and turns on a relay to send power to the amp. Convenient to use. There is the level gain adjustment to adjust the bass down without having to pull over and manually adjust the amplifier. Convert car stereo speaker wire output to RCA Cable outputs. In order to improve the sound quality, the function of RCA output can convert high to low. The high voltage signal output of the amplifier/speaker converts to low-voltage signal. Car audio speaker level converter wiring adapter allows to add 2 channel or mono amplifier or subwoofer to existing factory or aftermarket car stereo kit.