The PurestOne (tm) UC-1 UnderCounter Water Purifier Filter System. Save, Save, Save! Best Value in High-Quality, High-Performance Drinking Water Purification Filter Systems Available! Removes Harmful Chemicals, Microorganisms & Heavy Metals from Tap, Lake, River or Well Water! Advanced Sub-Micron Filtration Technology! Rated at 0.4 - 0.1 Micron! Meets NSF SUB-MICRON Class I Standards 42 & 53! Easy 20-Minute Installation For All Homes, Condominiums, Apartments, Cabins, Boats & R V's! Made in USA!