The SWC-45-1001 string wound filters are a cost-effective solution for the reduction of sand, silt, rust, dirt and scale particles. Hydronix string wound filter cartridges are made from 100% polypropylene cord. The Hydronix SWC-45-1001 filter cartridges are suitable for residential as well as commercial applications. This Hydronix polypropylene string wound filter fits most 10-inch Big Blue Filter Housings. The SWC series filters are suitable for both well and municipal water.