Whirlpool WHKF-WHPLBB Large Capacity 30 Micron Pleated Whole House Filter Cartridge Large Capacity Pleated Filter (9-3/4" H x 4-1/2" W) 30 micron nominal filtration rating 3 month filter life Reduces sand, dirt, silt, rust, and scale particles Tested and Certified by NSF International against NSF/ANSI 42 for material requirements.