The 400A fill valve revolutionized the toilet repair industry with pioneering innovation that works with, rather than against, water pressure. Easy to install & adjustable to fit most tanks & comes with a 1-year warranty. The 400A is engineered to last, and has all of the features you want, which has helped make it the #1 selling fill valve in the world. Anti-siphon design prevents contamination of the household drinking water. Water lever adjusting screw for best flush. Shank adjusts valve height from 9" to 14" to fit most tanks. Torque Guard locknut prevents thread damage from overtightening the nut.