That includes permanently lubricated upper and decrease ball bearings, the Lomanco 12-inch whirlybird turbine ventilator ensures lengthy life and no upkeep. It reduces wintry weather ice construct-up, in addition to power bills. Made with all-aluminum, rust-free construction, this internally braced turbine ventilator withstands winds as much as 147 MPH. With a rigid, spider-type construction, it is riveted at each connection. The ventilator features 21 air-foil curved vanes with rolled vane edges to deflect water and a vari-pitch base that adjusts to a 12/12 roof pitch. Designed for residential use best, this turbine ventilator comes with a lifetime warranty.