This total repair kit is used to repair a 1 1/2 inch anti-siphon vacuum breaker most commonly used in commercial, industrial applications to prevent the reverse flow of polluted water from entering into the potable water supply due to backsiphonage. This repair kit consists of a disc and disc float, a bonnet and O-ring. WATTS® Repair Kit, For Use With: Model 188A/288A/388 Anti-Siphon Vacuum Breaker