The Fits Kohler Class Five 3" Flapper Toilet Tank Flapper is designed to fit Kohler parts: 1016546 and 1042313. The exclusive longest lasting red rubber resists chlorine, bacteria, city water treatment, hard water, and well water. This is a large 3-1/4" replacement flapper designed to fit rectangular, black flush valves. The Fits Kohler Class Five 3" Flappers is compatible with the following Kohler two-piece models: Bancroft (3487, 4633), Cimarron (3496, 3497, 3499, 4634, 11465, 11466), Devonshire (3503, 4708) and Memoirs (3515, 3526, 4491, 4492). Flapper not compatible with 1-piece toilets or 2" flush valves. Made of flexible rubber for a tight seal and easy to install.