The NKIA 5908 is a high-performance combined needle roller / angular contact ball bearing. Unlike the "NKIB" series which handles axial loads in two directions, the "NKIA" series is designed to accommodate heavy radial loads and light axial (thrust) loads in one direction only.Single-Direction Location: Because it uses an angular contact ball component, it locates the shaft in one direction. For locating a shaft in both directions, two bearings must be mounted back-to-back.