The Kold Ster-il, Three Canister RO System purifies tap water without producing waste water, and without removing calcium and carbonates. It adsorbs and restricts the following: Lead, Mercury, Cadmium, Copper , Iron, Zinc, Volatile Organic Chemicals (VOC), tannins, Proteins, Dissolved Organics, Chlorine, Pesticides/Insecticides, Metal Particulates, Algae, Fungus, Giardia, Cryptospordium, and E. coli Bacteria.Water Flow Rate: 3.8 gpm at 40 psigMaterials of Construction: Canister - Polypropylene Top SANS Sump NSF, International Approved. Fin-L-Filter - UHMW Polyethylene End Caps w/ Acrylic & Polypropylene TubesFilter Media (Three Types of Filtration): Barrier Restriction, Adsorption, Absorption. Kold Ster-il System Provides Three Separate Methods of Filtration for your Health & Safety