20" Big Blue 5M Sediment Filter Pleated To Remove Sediment From Drinking Water - 5 Micron Filtration Rating Cartridge Dimensions: 4.25"O.D.  20"L, Fits a 20" Big Blue Filter Housing Excellent for use as a Prefilter or Whole House Filter Pleated design enhances dirt-holding capacity, Extending Life AMI Model No. H-FS20BB5PCAMI