50-Pack R4ZZ Bearings 1/4" x 5/8" Ball Bearing50 Pack R4ZZ Bearing 1 4" x 5 8" x 0. 196" Inch Shielded Miniature Ball Bearing The R4ZZ shielded ball bearing is a compact, high performance miniature bearing designed for precision applications that require smooth operation, low friction, and long lasting durability. With dimensions of 1 4" inner diameter, 5 8" outer diameter, and 0. 196" width, the R4ZZ is commonly used in electric motors, robotics, skate equipment, tools, and small mechanical