Genuine OEM Sloan repair part Vacuum breaker replacement for Royal, Regal and Crown series closet and urinal flush valves Used to repair Sloan Valve V-500 series vacuum breakers This kit includes a vacuum breaker insert, plastic spreader, and fiber washer The vacuum breaker acts as a one way valve that allows water to flow down thru it, but won't allow water to siphon back up Allows air to pass through the vents in the side of the vacuum breaker tube to break the vacuum that is created at the end of the flush cycle