X-type four-point contact ball bearings - JU series (double-sided sealing) feature a four-point contact raceway design with integrated heavy-duty contact rubber seals on both sides, supporting bidirectional axial loads while providing maximum protection against dust, water splashes, and contaminants in the harshest operating environments. Available in double-sealed configurations only, with bore diameters ranging from 30mm to 300mm. These bearings deliver compact design, high axial rigidity, superior sealing effectiveness, excellent moisture resistance, reliable grease retention, and maintenance-free operation in extreme conditions, making them ideal for heavy construction machinery slewing rings, offshore equipment, agricultural machinery, food processing equipment with washdown requirements, port material handling systems, and heavy-duty industrial applications where maximum environmental protection is essential.