Carries radial and moderate axial loads on a 20.0 mm shaft through a single row of balls running in a deep groove raceway. The 63004-A-2RSR design has a 20.0 mm bore, 42.0 mm outside diameter and 16.0 mm width, weighs 90.0 g and permits a limiting speed of 9700.0 1/min. The steel sheet metal cage (JN) guides the ball set, and the bore type Z indicates the raceway groove configuration. Both sides are fitted with seals (2RSR), keeping grease in and contamination out, so the bearing runs without additional external protection once mounted. Radial internal clearance is in the CN (Group N) range, suited for normal fit and temperature conditions without preload. This sealed, self-contained construction makes the bearing ready to install directly from stock, with no separate lubrication or shielding needed beyond periodic relubrication intervals as service life requires.