Big Blue Sediment Replacement Water Filters 4pcs (5 Micron) 4.5" x 20" Cartridges Replacement filters for Amazon item B01AR1EHFU or any standard size 20" Big Blue Housing 4 Big Blue (5 Micron) Sediment Filters for a Standard Size Big Blue Housings. Standard size filters 4.5x 20 All our filters are individually wrapped for freshness and protection while in shipment.