3x 10" CTO Carbon Block Water Filter Cartridges fit all standard 10" filter housings (approx. 2.5" cartridge diameter). Suitable for use with drinking water systems, reverse osmosis filters, aquarium filters, fed-water pole systems, and more. High-quality coconut shell carbon removes low levels of chlorine, organic compounds, pesticides, herbicides, and more. 5-micron particulate filtration also removes rust, dirt, sand, and sediment particles larger than 5 microns. This assures the user that the filter is high-quality and safe for drinking water use. Filter life: up to 12 months / 15,000 liters.