Hub material: aluminum As an alternative to steel versions, we recommend our KB4AL series for sizes 80 – 500 Shaft diameters: 10 – 70 mm High torsional rigidity, compensates for shaft misalignments with low restoring forces Easy installation and low inertia Ideal bellows coupling for servo motor connections such as machine tools, automation technology, packaging machines, and woodworking machinery Torque range: 18 – 500 Nm