The Harmsco HB-20-1W water filter is a 1 micron, highly efficient filter cartridge made of pleated Polyester-PLUS Filter media for low pressure drop, high flow cap. The Harmsco HB-20-1W water filter's pleated design offers up to 50% more surface area than competitive filters resulting in superior performance and increased contaminant removal, and longer filtration runs for fewer changeouts and less maintenance. Low pressure drop. Thermally bonded for longer usable life. FDA approved materials-NSF 61 certified and has an Engineered media for superior performance.