Polypropylene Wrapped Sediment Filter Cartridge. Pack of 4. Provides greater filtering surface area and longer life. The cartridge provides deeper filtration and removes more contaminants. Fits most standard 2.5 x 10 inch filter housings. Change every 4 to 6 months or every 50,000 to 70,000 gallons of water, depending on water quality. Replace regularly to maintain great tasting water. Made of 100% virgin, multi-layered, meltblown polypropylene microfibers, effectively captures various particles such as dirt, sand, rust, and more.