iSpring FP25BX4 20" Big Blue Whole House Water Filter 4.5" x 20" Sediment-Pack of 4, 20 x 4.5-5 Micron, White, 4 Piece Made of 100% Melt-Blown Polypropylene, 4-layer filtration 4.5" (Dia) x 20" (Length) Fits 20" Big Blue Water Filter Housings, such as Culligan whole house filter Individually wrapped for freshness Sold in 4 pieces pack Made of 100% Melt-Blown Polypropylene, 4-layer filtration Fits 20" Big Blue Water Filter Housings, such as Culligan whole house filter Individually wrapped for freshness Sold in 4 pieces pack