This is the iDatalink HRN-SR-GM1 GM Plug & Play T-Harness

The sGM1 is a vehicle-specific T-Harness designed to streamline the installation of aftermarket radios with the Maestro SR interface module. Compatible with select 2000–2009 Buick, Cadillac, Chevrolet, GMC, Hummer, Isuzu, and Pontiac models, this harness simplifies integration by providing a direct connection between your new head unit and the Maestro SR. Engineered for reliability and ease of use, it ensures a seamless upgrade to your in-vehicle audio system while maintaining dependable performance. With its head unit adapter-ready design, the sGM1 delivers a hassle-free solution for enhancing your car’s audio experience.