The Fluidmaster K-400H-039 PerforMAX Toilet Fill Valve and 2" Flapper Kit quickly solves common toilet problems such as; noisy toilet, running toilet, leaky toilet, and weak flush with one kit. A universal design, made for 2" flush valve toilets including Kohler, Toto, American Standard, and more. This kid includes the high performance PerforMAX Fill Valve, which is the quietest, most powerful fill valve on the market, with a code approved anti-siphon operation and easy to turn tank and bowl water level adjustment dials to control water use and save. The EZ-Twist height adjusts from 10" to 15" to fit most tanks. The kit also includes the PerforMAX Water-Saving 2" Toilet Flapper, which offers a dial adjustment to customize your water use. The solid frame ensures a secure seal, while the hard water resistant materials, and built-in Microban technology fight bacteria and breakdown.