Huco Flex M Coupling. Thin pressed steel membranes act as the pivotal members in these couplings. Torque is resolved to simple tensile stresses in opposing segments of the membranes. These couplings have near-infinite life and a dynamically balanced construction which makes them suitable for applications requiring high rotational speed and high-level motion integrity e.g. machine tools, robots, centrifuges, turbines, dynamometers.