For above ground pools up to 25,000 gallons. Comes with 1 mineral resevoir. A complete system of Minerals and Chlorine, with a precise dial for achieving at least 0.5 ppm chlorine level. Includes a Pool FrogŪ Cycler 6100 and Mineral Reservoir Series 5100. Cycler is in-line with 1.5" threaded ports for pools up to 25,000 gallons. Mineral Reservoir lasts 6 months. New features include new easy to remove cap, no tools required, and new control dial for more precise feeding. King Technology