The Builders Edge 22" Octagon (Net Free Venting Area: 54 Sq In) Provides Added Architectural Detail With Their Wood Grain Finish And Sharp Distinctive Characteristics Installation Is Easy With Our Wide Nailing Flange, Leveling Lines, And Adjustable Stop Gauge Our Patented Snap-On Trim Ring Hides Rough Cuts And Reduces Installation Time, While Providing A Finished Appearance Once The Vent Has Been Installed Brand Name: Builders Edge