The function of a sediment filter is to remove large and fine particles from the drinking water, such as sand, dirt, silt and rust particles Its made of fine melted polypropylene which is blown and spun in a cylinder-like form Melt blown with thermally bonded 100% Pure POLYPROPYLENE Microfibers Fits any standard 20-inch cartridge These filter cartridges provide high purity filtration and are organic free, pure PP media. Their outstanding chemical resistance, fibre-free melt-bonded media and excellent flow characteristics present a filter cartridge that meets the tough requirements of today's technology.