S1-A replacement sediment filter cartridge removes dirt, sand, silt, rust, and scale particles. 20 micron (nominal) filtration. Pleated cellulose construction for increased surface areas and strength. Filter life up to 3 months or 12,000 gallon. Use with filter model No. HF-150 (SKU 432717), HF-160, or HF-360 (432725). 2 per pack.