I bought this product to replace a much cheaper water filter from  Sainsbury's own range. Fortunately, I kept the Sainsbury's model and still use it as it works better than the Brita model and it uses much cheaper refills. The Elemaris cartridge exchange indicator failed after a couple of months and was a source of collection of green residue that could not be cleaned away. When it was working it was indicating changes were needed after a maximum of three weeks. I have been disappointed with the Brita product and do not intend buying another one.