For the actual function of the cartridges I can not say anything because they went straight back. Here in the text of the offer is repeatedly advertised with the TÜV seal of the cartridge, which also prompted me to buy. However delivered I got a completely different brand without TÜV Approval. At my request, the seller, to me in writing to file the TÜV test for the supplied cartridge, unfortunately followed no reaction. Only the rather speedy refund on Amazon is me here worth a star. Too bad it that way.