The WGB12B is a great "point of entry" filtration system for cleaning up heavily treated and chlorinated city water. Unlike "point of use" systems, the WGB12B will filter your water directly from the source. This means that water from every outlet in your home will have passed through this filter.  This system comes standard with a 5-micron CTO coconut shell carbon block filter. Block carbon is more effective than other forms of carbon in that it is finely ground up carbon packed into a solidified block. This means they have a higher density than other types of carbon filters and are therefore more effective in removing their targeted contaminants. The carbon block filter knocks out bad tastes and odors, removes over 90% of sediment and chlorine from the water, and is highly effective on chemicals like pesticides, herbicides, and industrial chemicals.  If you are on city water, your local water utility must meet very strict Federal and State standards for purity. Almost all municipally treated water is chlorinated, and this can affect the taste and create odors in the water. The WGB12B filtration system will remove these tastes and odors. If you are on a private well or spring, you should have your water tested, and you also may want to contact our technical staff for help in selecting the best filter system for your water chemistry.  Features: - Filters the incoming water supply for your entire home - Removes up to 90% of sediment, chlorine, pesticides, herbicides, industrial solvents, and various other contaminants - 20" x 4.5" filter cartridge allows for minimal pressure reduction and filters up to 100,000 gallons. 1" input and output ports handle up to 15 gallons per minute -  CTO Carbon Block filter uses high-quality coconut shell carbon for maximum filtration efficiency and filter life