Upgrade your vehicle's performance with the Denso 3421 Iridium Long Life Spark Plug. This tune-up kit includes four high-quality spark plugs designed for the SK20HR11 model. Featuring advanced iridium technology, these plugs provide superior ignition efficiency, ensuring a smoother engine start and improved fuel economy. Their long-lasting durability means you’ll spend less time on replacements and more time on the road. Perfect for enhancing your vehicle's performance, these spark plugs are a reliable choice for any car enthusiast looking to optimize their engine's power and efficiency.