Ventamatic Wind Turbine Attic Exhaust - Internal Bracing, Aluminum, 12in., Weathered Gray, Model# CX12IBALWG Internally braced for high wind resistance Premium-grade stainless steel dual ball bearings with integrated molded shield to protect bearings raceway Adjusts to 12/12 pitch High-quality aluminum construction for extra durability Handsome powder-coat finish withstands weather extremes