18 X 8 (Duct Opening Size) Air Register Adjustable Aluminum Louvers with Damper (Color-White) Bar Face Adjustable Vanes 18x8 Stylish 1 or 2 way register for ceiling or sidewall supply air. Aluminum construction. Vanes are adjustable left and right . Manual shutter damper opens and closes with lever. Color-White. Comes with mounting screws. Fits 18" x 8" opening. Register face is 19-3/4" x 9-3/4".