12IN ML INT BRC TURBINE

12" standard internally braced wind turbine attic exhaust vent. Galvanized steel construction - mill finish. Co-polymer bearing system for quiet, long lasting, and smooth operation - adjusts to 6/12 pitch. Tested to ensure durability and performance in extreme temperatures and high winds. This exhaust vent requires adequate soffit intake vents. Requires 432 sq in of NFA,(Net Free Area). Includes: Base and riser. Lifetime limited warranty.