Gs-10ro-g-1/4" john guest 2" x 10", the Pentek gs-10ro-g inline filter cartridge replacement is a 10" in-line filter which uses coconut shell granular activated carbon (gac) for cleaner, better tasting water. It can be utilized in numerous applications such as reverse osmosis systems, food service, water coolers, refrigerators, ice makers, vending equipment, under sink filter systems, and more to reduce the bad taste and odor of chlorine as well as common particulate matter such as sediment, dirt, rust, silt, sand, and so on.