The NGK ILFR6G-E 4212 Laser Iridium Spark Plugs are specifically designed for Mercury Verado L6 200-400 HP outboard engines, delivering optimal ignition performance, fuel efficiency, and durability in demanding marine environments. With a fine-wire iridium center electrode, these spark plugs provide precise ignition, improved throttle response, and enhanced fuel combustion, making them the ideal choice for boating enthusiasts, professional fishermen, and marine service professionals. Built with laser-welded iridium technology, these spark plugs offer exceptional longevity and wear resistance, significantly reducing the need for frequent replacements. The corrosion-resistant construction ensures reliable operation in saltwater and freshwater applications, maintaining consistent ignition performance and preventing misfires. Compatible with Mercury Verado L6 engines (200HP, 225HP, 250HP, 275HP, 300HP, 350HP, and 400HP), this set of six spark plugs is an essential maintenance upgrade for maintaining peak engine efficiency and reliability.