A further development of the often copied A series is the T-Flex. Here, too, the essential feature is that the elastic inner part can be lifted out radially without having to move the coupling hubs. In contrast to the A series, the elastic inner part of the T-Flex is not subjected to shear stress. The retaining ring is designed here with a form-fit driver, so that the power density of this coupling system is significantly higher. This coupling system is also available with spacer.