This is a separate cylindrical inner ring designed for use with needle roller bearings that operate without an integral inner ring, providing a hardened, ground raceway surface for the rolling elements. It has a bore diameter of 20.0 mm, a width of 16.0 mm, and a net mass of 16.7 g, matching the XL series geometry for correct axial and radial fit within the corresponding outer bearing components. As a separate ring, it allows the raceway diameter and load-carrying surface to be matched precisely to the shaft, letting the designer select the fit and surface hardness independently from the housing bearing. Since it carries no seals or integrated lubrication, grease or oil supply and sealing arrangement must be provided by the surrounding assembly, and mounting tolerances should be selected according to the required running accuracy and load direction.