Graver High Flow RF Series filters features a multi-layer pleated polypropylene media in a larger geometry to handle higher flows with fewer filter elements resulting in much faster, easier filter changeouts. construction with optimized surface area. Designed to retrofits competitive large diameter filter housings utilizing the “740” design or the large diameter 338 o-ring design, the all polypropylene construction provides for a high level of chemical compatibility while meeting NSF/ANSI STD 61.