OWS 12' Windmill Aeration SystemOutdoor Water Solutions Galvanized traditional windmills are designed to last for 15, 20, or even 30 years. These windmills are made in the USA. All of our windmills feature unique BalCam II Technology that spreads the workload across three internally mounted sealed bearings. These Windmill Aeration Systems include: Air Stone Diffuser Foot Valve 100' of 1 2" air line Self governing head to protect the unit in high winds Larger check valves The 12'