NW16 3 Stage Undersink Drinking Water Filter SystemUSAGE Used for drinking water filtering under sink. DESCRIPTION The NW16 undersink drinking water filter system has 3 stages of water filtration which drastically reduces the following from your drinking water: Stage 1 5 micron Sediment Filter reduces sediment, lime, dirt, rust and visible particles down to 5 micron. Stage 2 Carbon Block Filter reduces chlorine, organic contaminants, pesticides, and other toxins. Stage 3 Granular Activated Carbon