Description 2 &1/2-inch Flush Valve Assembly for Two Piece Toilets  Size 2.5 inch flush valve assembly for two piece toilets. Designed for two-piece toilets with a 2.5 inch flush hole. Includes flush valve and 2.5 inch flapper valve. Flush Valves in 2.5 inch Toilets need to be slightly smaller than 2.5 inch to fit properly. Flush Valve Easy Measuring Tips – Video One piece or Two piece which is right for you? Video