The product is an OEM stereo audio amplifier amp for BMW 5 Series vehicles (528I, 535I, 550I) manufactured between 2010-2013. Produced by Harman Kardon, the amplifier is designed specifically for these models, providing high-quality sound and performance. The OE/OEM part numbers listed ensure a perfect fit and compatibility with the specified BMW vehicles, ensuring a seamless integration of the audio system for an enhanced driving experience.