Filter 6. Reduces 9 contaminants, including lead and mercury, pesticides and industrial chemicals NSF (National Sanitation Foundation) certified. Certified to fit these leading refrigerator brands: Whirlpool, Maytag, KitchenAid, Jenn-Air and Amana. Used in top freezer refrigerators. Filter compartment is in the bottom left corner of the refrigerator. Replace filter ever 6 months or 120 gallons to maximize contaminant reduction.