Big Blue Pleated Sediment Water Filters 4 Washable 4.5 x 20 Cardridges -5 Micron 4 Big Blue Pleated (5 Micron) Sediment Filters for a Standard Size 20" Big Blue Housing. FREE SHIPPING Standard Size 4.5" x 20" Pleated filters have a larger filter surface area, longer cartridge life, higher flow rate, greater dirt holding capacity, lower pressure drop, and more efficient when compared to other sediment filters. They are individually wrapped for freshness and protection while in shipment.