ACDelco D505A GM Original Equipment Ignition Coil High quality coated windings to improve durability and provide protection against internal shorts and dielectric breakdown Silicone steel plates surrounding the ignition coil correctly match the original part size and number exactly Laminations are coated to hinder corrosion and many feature molded plastic protection to help ensure that nothing is exposed GM-recommended replacement part for your GM vehicles original factory component Offering the quality, reliability, and durability of GM OE