The Fluidmaster 400H PerforMAX Universal High-Performance Toilet Fill Valve sets the standard for performance, but also remains quick and easy to install. Featuring new and improved step-by-step pamphlet style instructions, and a pre-installed shank washer for the fastest and simplest install possible. The most powerful fill valve in the market, with 2X greater refill rates than standard models, and ultra-quiet operation. You can customize your water use per flush depending on your needs, or toilet model with the easy-to-turn adjustment dials. Set for more or less water in either the tank or bowl. This universal toilet fill valve design is built to work with most toilets and brands. Best for use in 1.28 HET and 1.6 GPF toilets but can also be used with pre-1994 3.5 GPF toilets. The PerforMAX fill valve is a code approved, anti-siphon design that won’t contaminate the fresh water supply. Save-water and stop toilet noise with Fluidmaster’s 400H PerforMAX Toilet Fill Valve.