The Metra 40-EU10 is a European antenna adapter engineered for select amplified European vehicle antenna systems. Designed for aftermarket radio installations, this adapter retains factory AM/FM antenna functionality while converting European-style antenna connections to the standard Motorola connector used by most aftermarket multimedia radios. (metraonline.com) Built with integrated powered antenna retention circuitry, the 40-EU10 helps maintain proper antenna amplifier operation in many Audi, Volkswagen, BMW, Mercedes-Benz, and other European vehicles equipped with amplified factory antenna systems. This ensures stronger AM/FM reception after upgrading to Apple CarPlay®, Android Auto™, Bluetooth®, navigation, and touchscreen multimedia systems. (metraonline.com) Features European amplified antenna adapter Retains factory AM/FM antenna functionality Converts European antenna connection to Motorola plug Integrated powered antenna retention Plug-and-play installation Designed for amplified antenna systems OEM-quality molded connectors Maintains factory radio signal strength Simplifies aftermarket multimedia installs Designed for European vehicle applications (metraonline.com) Specifications Product Type: Antenna Adapter Vehicle Compatibility: Select European Vehicles Connector Type: European to Motorola Amplified Antenna Support: Yes Installation Type: Plug-And-Play Power Lead: Blue antenna amplifier turn-on wire (metraonline.com) Common Vehicle Compatibility Audi A4 Audi A6 Volkswagen Jetta Volkswagen Golf BMW 3-Series BMW 5-Series Mercedes-Benz C-Class Mercedes-Benz E-Class (Exact compatibility varies depending on year, trim level, and factory antenna configuration.) Included In The Box 40-EU10 antenna adapter Integrated power wire lead (metraonline.com) Installation Notes Blue wire connects to radio antenna/amp turn-on output Required on many amplified European antenna systems Additional wiring harness required for radio installation Professional installation recommended