I purchased this about four years ago from Takagi. I used it for about six months, but then I bought a larger, installed hydrogen water purifier, so I washed it and stored it. I'm selling it now because it's a waste to keep it. The instructions are included, but I couldn't find the box. I've confirmed that it works, but there are some limescale marks on the main unit. Please note that you must use purified water to make hydrogen water. It takes up the space of one CD. Freshly made hydrogen water is best, so in the summer, you can put the unit and water in the refrigerator to cool it and then use it directly. I highly recommend this to anyone interested in trying hydrogen water. The pH test solution is unopened and will be included.