1 1/4" Watts Series LF288A Anti-Siphon Vacuum Breaker is designed to prevent the reverse flow of polluted water from entering into the potable water supply due to backsiphonage. It features a full size bore to assure pipe size capacity and maximum flow. It is ideal for low flow, non-continuous hot or cold water health hazard installations such as on laboratory equipment. Bronze body with a chemical resistant silicone seat disc and atmospheric vent. Maximum pressure: 125psi