GM Genuine Parts Ignition Coils are designed, engineered, and tested to rigorous standards, and are backed by General Motors. It increases electrical system voltage to help ignite the air/fuel mixture as the starting and charging system starts the engine, maintains the battery's charge, and provides power to the electrical accessories while the engine is running. A GM Genuine Parts Ignition Coil uses pure copper windings to improve durability and provide higher resistance to internal shorts and dielectric breakdown. Because the number and shape of the laminations determine the output characteristics of an ignition coil, ACDelco ensures that the silicone steel plates surrounding the coil correctly match the original part size and number. Since steel laminations work best when they are new, shiny, and clean, ACDelco laminations are coated to hinder corrosion and many feature molded plastic protection to help ensure that nothing is exposed. GM Genuine Parts are the true OE parts installed during the production of or validated by General Motors for GM vehicles. Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE).