Crystal Quest CQE-RC-04046 Faucet Mount Filter Cartridge The CRYSTAL QUEST CQE-RC-04046 Faucet Mount Water Filter Cartridge is a5-stage water filterthat is designed to reduce many contaminants from water In Stages 1 and 5, water passes through pre and post one-micron filter pads, which reduces suspended particles such as silt, sediment, cyst, sand, rust, dirt, and other undissolved matter In Stage 2, water passes through Granulated Activated Carbon (GAC), which reduces bad tastes and odors, pesticides and chemicals that are linked to cancer risks