ACDelco D302A Distributor Cap Have metal inserts designed to provide the best possible fit to ensure maximum conductivity between the distributor towers and spark plug wires Easy-to-read locator keys on caps make proper installation simple Equipped with a full anti-arc barrier to reduce the possibility of secondary voltage arcs that can cause an engine to misfire GM-recommended replacement part for your GM vehicles original factory component Offering the quality, reliability, and durability of GM OE