DESIGNED TO FIT: side-by-side refrigerators from Whirlpool, KitchenAid and Kenmore that use a quarter-turn filter located in the bottom grille 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