The 4 pcs MR148ZZ ball bearings are truly miniature masterpieces, measuring just 8x14x4 mm. They're designed for precision and compact use, making them perfect for applications where space and precision are at a premium. These bearings are part of a larger grade, known as "medium ball size," which offers a balance between smoothness and load-carrying capacity. The MR148ZZ grade has a higher load capacity than other sizes in its family, providing the perfect combination of durability and efficiency. Each of these 4 bearings can be individually inspected, ensuring they meet the highest standards before being packaged and shipped to their next user.