The Fluidmaster B212-10 replacement seal bulk 10-pack for Model #400A fill valves is a quick and easy way to restore your toilet fill valves performance. A direct replacement seal which fits the universal Fluidmaster 400A toilet fill valve, the #1 selling toilet fill valve worldwide. This part offers an easy way to solve common toilet fill problems without the need of purchasing a new toilet fill valve. Use this design to extend the life of an otherwise effective fill valve. Built with quality in mind this design comes with a 1 year warranty.