2 Gallon Refrigerator Unit filters and alkalinizes up to 120 Gallons of water per filter while retaining Beneficial Trace Minerals. OPTI Water will filter about 1 gallon per 1hour. Compared to other competitors we filter slow, but we remove more contaminants. Saves money on water and reduce wasteful plastic bottles while drinking delicious alkaline water that is pure. Easy to install and use, the OPTI Chill works by simply filling the top reservoir with water and letting gravity filter through the Ionic Filter. No Electricity or Plumbing required. Naturally Alkalizes water up to 9.0pH Filters Proudly Made in the USA Product of USA 2 Gallon Refrigerator Unit Proven Test Technology Filters 99.99% of contaminants, bad tastes and odors. Removes up to 99.99% of Harmful Contaminants. Naturally Enhances Alkalinity up to pH-9.0 Retains Beneficial Trace Minerals Filtered water remains alkaline for over 90 days! Filters up to 120 Gallons per filter Saves money on water and reduces wasteful plastic bottles The OPTI Chill provides fresh, clean alkaline water at a fraction of the price. Easy to install and use, the OPTI Chill works by simply filling the top reservoir with water and letting gravity filter through the Ionic Filter. (This filter is designed to be used as a drinking water filter for use with chlorinated municipal tap water.)* The top reservoir is designed to always keep about 1 inch of water so please do not be alarmed. We designed this so the filter is always in contact with the water and OPTImizing it.