This Sony XM-404EQX 4-Channel Car Amplifier with Equalizer is a vintage piece of Japanese car audio equipment. It is untested, but it is a highly sought after item for collectors and enthusiasts. With four channels and a built-in equalizer, this amplifier is perfect for any car audio setup. The brand Sony is known for producing high-quality electronics, and this amplifier is no exception. Its retro design and functionality make it a unique addition to any car audio system.