Models will now have an E on the sticker indicating the new counterfeit proof models. They will fit all existing units using a XWF filter | GE fit - Compatible with select GE side-by-side and bottom-freezer refrigerators | Premium filtration - Certified to reduce chlorine-resistant cysts, lead, select pharmaceuticals and 50 other impurities | Lead removal - Lead is invisible, tasteless and odorless when present in water. Reduce lead with this under-sink filtration system | Pharmaceuticals reduction - Reduces select pharmaceuticals, including ibuprofen, progesterone, atenolol, trimethoprim & fluoxetine. * (*Impurities not necessarily in all users’ water) | PFOA/PFOS reduction - Reduces 99% of Perfluorooctanoic acid (PFOA) and Perfluorooctaine Sulfonate (PFOS)