This 12-blade Outdoor Water Solutions Windmill Head Kit aerates a pond or lake from the bottom up, reducing algae, bacteria and odor. The wind-driven system adds oxygen and prevents pond stratification, helping to reduce fish kills. Aeration also keeps ponds from freezing over in the winter, aiding waterfowl hunting. Kit includes 100ft. of poly tubing and an Airstone diffuser. This windmill head will fit on most windmill towers (not included).