A Practical and Quality focused filter manufacturer SF Filter (Shuangfa) is one of the earliest filter manufacturer in China, established in 1991, WQA membership since 2016, focused on filter cartridges for water/liquid filtration and purification. We believe data doesn't lie, at SF, research and quality control protocols are developed based on performance. Our product includes String wound filter cartridges, PP melt blown filter cartridges, activated carbon filter cartridges, pleated filter cartridges and filter system etc.