For radial couplings, two magnets (systems) run in one other. The torque depends on the dimensioning, the magnetic material, the number of poles and the air gap. The air gap (distance between the magnets) should be kept as low as possible in order to achieve the highest possible torque. The partition should be made of magnetically non-conductive material. It should also conduct electricity poorly, to avoid disturbing influences by eddy current at high speeds. The startup speed should be selected in such a way that skipping of the magnetic poles is avoided. The torque is the same at all speeds.