The Repair Salvage Sleeve for 4B 6B 3.9L 4.5L 5.9L Cummins is a high-quality and cost-efficient solution for repairing damaged engine sleeves. Constructed from durable materials, this sleeve is designed to withstand the demands of daily use and provide long-lasting performance. It is the perfect fit for 4B 6B 3.9L 4.5L 5.9L Cummins engine models, and is a direct replacement for OEM part number 3904166. Installation is simple and straightforward, making it easy for anyone to use. With a one year unlimited mileage warranty, you can trust that it's built to last and will provide you with the peace of mind you need.