I picked these up from the ArtDeco display in the local department store after seeing them in the German version of Glamour magazine. I have a slight addiction to nail polishes, and despite using a basecoat, sometimes my nails yellow - these fizzy balls are suppost to remove this discoloration. In order to use these, you're supposed to take 2-3 and put them into a bowl of warm water, and soak your hands for 5-10 minutes. Does the product work? So-so. There is a change in the state of the discoloration of my nails after use of the product, but this change is normally so small that I have to repeat the procedure a second time, and sometimes that's STILL not enough for a satisfactory result. While I aknowledge that this product does work, albeit weakly, I'm going to have to give it a low rating and a no-buy. 9eu is too much for a product that has to be used multiple times a sitting.