This 12-blade Outdoor Water Solutions Windmill Aeration System stands 23ft. tall to the top and can aerate ponds up to 2 or 3 acres in size with as little as 3–5 mph winds. The wind-driven system aerates a pond or lake from the bottom up, reducing algae, bacteria and odor, while adding oxygen and preventing pond stratification, which helps to reduce fish kills. Aeration also keeps ponds from freezing over in the winter, aiding waterfowl hunting. Complete system includes 20ft.H tower, windmill head, 100ft. of 1/2in. dia. poly tubing, 50ft. of 1/2in. weighted airline, 1 Airstone diffuser with backflow valve, 1 Airstone housing bucket, 1 duck decoy, and 1 set of tower hinges. Eye-catching blue and white finish.