I often take water in different places, measure the hardness, this device is still the leader, 7-8 units (the average value is about 20, tap water is 130-200, after the filter it is 70-100). Moreover, I measured it at different times.
Filters are changed often, it is convenient to put a bottle on the side. Payment via "Pay" is present on the website.
For a coffee maker/coffee machine, generally the best solution. And coffee (or tea) is richer and the technique will last a long time.