This patent-pending series marks a revolution of our mid-range ventilation fans. It gives professionals the flexibility to handle new construction or room-side retrofit installations from one hard-working product line with a full range of operating points. Innovations include foldable mounting ears and new damper and housing technology that improve building airtightness like never before. And all with new grille designs that are at home in any decor. - See more at: http://www.broan.com/invent#sthash.G1112cPg.dpuf