YUNDA FILTER is a professional manufacturer for all kinds of Water Filters and Elements, such as filter housing, filter cartridge, connector, valve, UV light, FRP, etc. YUNDA FILTER has over 10 years export experience. Direct price and good service. Hollow Fiber uses quality Polypropylene (PP), UPVC or Polyacrylonitrile (PAN) as material to make filter cartridges. The micron rate is 0.1 micron or 0.01 micron. It 100% removes bacteria.