This valve spring fit is designed for Cummins Engine ISX QSX X15. It is made with high-quality materials and is suitable for use in engines. The OE/OEM part number for this valve spring fit is 3681001, and the manufacturer part number is 3681001, 3679551, and 4965891. This valve spring fit is made in China and is perfect for those looking to replace their old or damaged valve spring fit. It is compatible with various types of valve guides, springs, and parts, making it a versatile choice for engine enthusiasts.