This expansion plugs with the manufacturer part number 4017621 are designed to fit Cummins engines including KTA19, KTA38, KTA50, and NT855. The plugs have been made in China and are sold as a unit of 1. Ideal for those looking to replace old or worn-out expansion plugs, these units are a reliable and cost-effective solution. With their durable construction and high-quality materials, they are sure to provide years of dependable service. Whether you're a commercial truck owner or just someone looking to keep your engine in top shape, these expansion plugs are a great choice.