Korky 2000BP Classic Plus Flapper Larger ball design to stay open longer and ensure a tight seal on 5 and 7 gallon toilets Fits older style brass flush valves Premium red Chlorazone rubber resists chlorine 5 year warranty Committed to Quality Made in USA Longest Lasting Products Quick &amp; Easy to Install Bacteria, chloramines, chlorine, city water treatment, hard water, well water and rust