KENT has the best gravity water purification technology. Kent Gravity Water Purifiers have a multi-stage UF Membrane purification system that gives truly pure water and protects you from water-borne diseases. The unique UF Membrane's pores are so fine, that they do not allow any Bacteria or even Cyst to pass through. Thus making the drinking water pure without use of any chemicals like Chlorine, Bromine or Iodine.