The WeatherPRO Turbine Ball Replacement Top can be installed on an existing base from a whirlybird or turbine vent of either 12" or 14". It is intended for a sloped and shingled roof to ventilate hot, moist attic air as part of a balanced ventilation system. It blocks out water and snow thanks to drain openings.
Installed within 24" of the roof's peak. It UV, crush, dent and corrosion resistant. No maintenance required. This product is backed by a 35-year limited warranty.