The Hydronix SDC-25-1005 6-Pack Sediment Depth Cartridges are 5 micron sediment filters measuring 9-7/8-inch x 2-1/2-inchs. The Hydronix SDC-25-1005 Polypropylene Prefilter has graded density for higher dirt-holding capacity and are made of 100% pure polypropylene. These filters are perfect prefilters for GAC filters, RO systems, DI Systems, ice machines, wineries, and many more. The Hydronix SDC-25-1005 is tested and certified by NSF International to ANSI/NSF Standard 42 for material requirements only.