The 3M™ Aqua-Pure™ Whole House Standard Diameter Water Filter Drop-in Replacement Cartridge AP110 for the AP100 & standard and large diameter Stainless Steel Housing Series, is a great choice in water filtration. This standard 2.5 in diameter drop-in cartridge is manufacturer tested and verified to reduce sediment down to 5 micron nominal. Its rigid construction from our proprietary polypropylene manufacturing process, helps to eliminate in unloading in of sediment due to variances in water pressure, sometimes referred to as water hammer.