New & Improved for 2025 - Iron reducing media now performs better over a broader pH range. Larger cap and thicker shell improves durability. Whole House Iron Water Filter Replacement Cartridge 20 micron - 20 in. x 4.5 in. Fits: Home Master Water Filter and 20 in. Big Blue water filter housing. Ideal Iron treatment for high flow applications. Radial Flow design provides excellent iron reduction with minimal pressure drop (less than 1 psi pressure drop). Effectively reduces iron and manganese up to 3 PPM combined contaminant load. Reduces pipe and water heater damage caused by iron, hydrogen sulfide, and manganese. Lifecycle based upon combined iron and manganese content present. In the box: replacement filter cartridge.