Sloan 3323183 Part SLOAN valve high back pressure vacuum breaker repair kit for all SLOAN flushometers. This kit includes a friction ring, baffle, and vacuum breaker sack This upgraded kit features a skirt around the base to prevent any leaking caused by the higher back pressure caused by low consumption Fixtures 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