Green Coconut Carbon Filters are the carbon block pre-filter designed for Stealth-RO™ and smallBoy® systems, effectively reducing chlorine, organic chemicals, mercury, lead, PCBs, sulfur, and heavy metals. These filters remove up to 99% of chlorine, sediment, rust, and silt and feature a 10-micron nominal filtration, rated at 1 GPM. They have a greater dirt load capacity, improved flow efficiency, and no release of carbon fines, resulting in reduced rinse time. For optimal performance, replace after 3,000 gallons for smallBoy® systems and after 1,250 gallons for Stealth-RO®. HydroLogic® Green Coconut Carbon Filter Features: Removes up to 99% chlorine, sediment, rust, and silt Rated at 1 GPM 10 micron nominal filtration No release of carbon fines Reduced rinse time due to carbon fines Greater dirt load capacity and flow efficiencies For Stealth-RO™ and smallBoy® Systems Replace every 3,000 gallons for smallBoy® Replace every 1,250 gallons for Stealth-RO® Dimensions: 9.75 in. H x 2.75 in. W