Powder Coated 20 ft Windmill Aeration System Feeder Ask us for advice on Timer:No Timer Ask us for advice on the best way to protect your assets from birds using lasers (1) Dual Disc Diffuser The blade diameter on all units is a full 73″ in diameter which is the largest windmill head on the market for pond aeration The Wind Driven Aeration System offers:New “BalCam II” technology minimizes bearing fatigue with new Stainless Steel componentsPatent pending new designFast & Easy AssemblyManufactured with high quality 18 gauge galvanized steelNewly redesigned blades and front dome assembly for better air flowSelf governing head to protect the unit in high windsNew secure locking mechanism that attaches the windmill head to shaftLarger check valves and upgraded ½” airline to handle the increased air that is producedHigh Air Output – 3