3x AH-CTO5 AquaHouse 10" Carbon Block water filter cartridges, fits all standard 10" water filter housings (cartridge diameter 2.5"). Suitable for use with drinking water, reverse osmosis systems, aquarium filters, water fed pole systems, and more. High quality coconut shell carbon removes high levels of Chlorine and other chemicals. 5 Micron rated particulate filtration also removes levels of rust, dirt, sand and sediment particles larger than 5 Microns in size. Premium water filter meets NSF/ANSI 42 standard for material safety, and has been tested for chlorine reduction. Suitable to be used as a standalone filter, or as a pre-filter stage within reverse osmsosis systems. Recommended filter life: up to 12 months / 15,000 litres, dependant upon incoming water quality. AquaHouse branded filter, Aquahouse is a registered trademark of Water Filter Man Ltd.