Culligan S1A Whole House Standard Water Filter, 16,000 Gallons The S1A pleated cellulose standard duty filtration cartridge works in HF-150A, HF-160, HF-360A, and HF-365 whole house filtration systems Perfect for residential homes, helps protect appliances and pluming from sediment and scale Features a flow rate of 4 GPM and filter life of 4 months/16,000 gallons (depending on usage and water conditions) Not recommended for untreated well water Reduces: sediment, rust, scale, dirt, coarse sand and sand The HF-150A is tested and certified by WQA against NSF/ANSI Standard 42 for materials safety and structural integrity only Micron rating of 20 (the smaller the micron rating, the smaller size patricle the cartridge will filter) Compatible with Culligan model HF-150A, HF-160, HF-360A, and HF-365 Fits HF-150 & HF-360 Medium-fine (20-micron) sediment filtration: sand, silt, dirt, rust particles and scale particles. Level 2 Basic Filtration Cartridge life 4 months or 16,000 gallons Not recommended for use with non-treated well water supplies