Dual Filter with U.V. Add On” This unit is designed for low T.D.S. water and unchlorinated water. The U.V. is optional, but recommended for unchlorinated water sources. The unit is designed with a 1 micron sediment filter, to remove particulate, 0.5 micron carbon block, to remove chemicals, chlorine, herbicides, pesticides, bad taste and odors. The carbon block will also remove lead by using a “cation resin” and, since the carbon block is sub-micron rated, it will also skim out bacteria.