39 has multiple threaded holes 45 into which there can be screwed screws 46 which extends through the installation holes 16 in the fastening flange 14 of the containment can 10 it is thereby possible within a magnetic clutch size to interchange different containment cans 10 of different pressure stages or strengths and or different materials furthermore on the side situated opposite the mounting flange 40 there is provided a ring 47 which extends further in an axial direction into the interior space 11 which ring forms a run on safeguard and prevents contact between the magnets 37 of the outer rotor 38 and the main body 12 of the containment can 10 the outer contour of the adapter element 39 has in each case a substantially conical profile here proceeding substantially from the mounting flange 40 the adapter element 39 narrows toward the ring 47 the inner contour of the adapter element 39 is at least partially of narrowing form in the embodiment illustrated in fig2 that end of the outer rotor 38 which points in the direction of the casing cover 4 has a radially encircling projection 48 facing toward the ring 47 which projection in the possible case of an outer rotor.