DESIGNED TO FIT: Top and Bottom-Freezer refrigerators from Whirlpool, KitchenAid and Kenmore with a quarter-turn filter located in the grille at the bottom of the fridge NSF 42 CERTIFIED: Each Tier1 refrigerator filter is tested and certified for materials and structural integrity requirements HIGH EFFICIENCY FILTRATION: Reduces Chlorine Taste & Odor, Rust and Corrosion, Sand Sediment, Silt, and Turbidity for 300 gallons or 6 months, depending on water usage and quality