Watts Brass & Tubular 765DBV, Febco, 3/4", 765 Pressure Vacuum Breaker EDP , Used To Protect Against Health Hazard & Non-Health Hazard Backsiphonage Conditions For Lawn Sprinkler Irrigation Systems, Swimming Pools, Laundries & Industrial Plants, All Bronze Body For Durability With 1 Check Valve & An Air Opening In On Assembly, Lightweight Poppet Seals Air Opening Under Minimum Flow Conditions, All Internal Parts Serviceable In Line From Top Of Unit, Designed For Minimal Head Loss, Engineered Plastic Bonnet Protects Valve Body Form Freeze Damage, To Repair Damaged Bonnet & Poppett Use Ron's Bobbet Poppett Repair Kit Febco #953422, Pressure Vacuum Breaker Assemblies Should Be Installed At Least 12" Above The Highest Piping & Outlet Downstream Of The Assembly To Preclude Backpressure, Assemblies Should Be Installed So They Are Easily Accessible For Maintenance & Periodic Tests, Asse 1020, Csa B64.1.2 & UPC Code Approved & Listed.