Axially symmetric races to support radial loads while maintaining high speeds and rotational accuracy Conforms to ABEC 1 precision standard for performance within a narrow range of variation Deep grooves support heavier loads than standard grooves and keep balls stable at high speeds CN (normal) radial internal clearance for applications that do not involve thermal expansion or atypical precision Steel cage evenly spaces the rollers for even load distribution and prevents contact to reduce friction, vibrations, and noise