The Korky Ultra Water Saver Flapper is the most universal 2" flapper available. The flapper adjusts to match original toilet settings and eliminates water waste by decreasing the amount of water flushed. Ideal for all standard 2 inch toilets, including: 1.28, 1.6, 3.5 and 5 GPF (gallons per flush). The exclusive longest lasting red rubber resists chlorine, bacteria, city water treatment, hard water, and well water. Recommended by the Clorox help line, this Korky flapper is proven longest lasting. The adjustable flapper has multiple settings to ensure it fits popular 2" toilet models: American Standard Cadet (4029, 4078, 4083, 4053, 4650), Monarch (4003), Mainstream (4061), Evolution 2 Flowise (4061), Kohler Wellworth (K-4620), Wellworth (K-4519), and TOTO (706). Made of flexible rubber for a tight seal and easy to install.