Fluidmaster Performax 2" Red Adjust-A-Flush Toilet Flapper. This innovative flapper features adjustable dials that allow you to customize the flush volume for a more efficient and effective performance. It fits most toilets, including 1.6 gallon models, and is made from durable thermoplastic material that resists harsh water conditions. The built-in Microban technology helps prevent flapper breakdown due to bacteria, ensuring long-lasting performance. Backed by a five-year warranty.