The PP-30-20-DOE-B cartridge filter is an absolute rated pleated polypropylene filter, manufactured by Harmsco Filtration. The All-Poly absolute rated pleat is rated at 20 micron. This filter has a nominal length of 30 inches and has a DOE (double open end) end cap. The filter has a B (Buna) gasket. These cartridges are 99.98% efficient (Beta 5000) at their designated micron rating. USP Class VI – 121* C (250*F) for plastics. FDA listed materials: Manufactured from materials which are listed for food contact applications in Title 21 of U.S. Code of Federal Regulations.