The 618 (6800) and 619 (6900) Series represent the most space-efficient design in the deep groove ball bearing family. These "ultra-light" series offer an extremely small cross-section relative to their bore diameter. This allows for larger shaft diameters and more compact housing designs without increasing the overall footprint. Common in medical equipment, optical devices, and bicycle components, our 618 and 619 series (including specialized sizes like 619/8) provide the perfect balance between minimal weight and reliable rotational performance.