Tailor-made filter cartridges, use it in my pot ... BWT perform their duties perfectly, and subjectively, I must say that they are more durable than the original BWT cartridge. After a month I have no trace still a calcification in my kettle. It is a single household is thus filtered anyway not much water but in the original BWT cartridge filter performance was towards the end of the month no longer so good, so I read through the water several times.
