Genesis Water Technologies GWT-P-20P-.5 Polypropylene String-Wound Depth Replacement Sediment Filter Unit with 0.5 Micron Rating Measuring 20-Inch X 2.5-Inch Stringwound polypropylene replacement filter .5 micron rated to remove even fine particulates Excellent for prefiltration to protect higher value filters and reverse osmosis units Standard 20 inch by 2.5 inch size Proudly made in America