Accord ABBBWHB18 Baseboard Register with Wicker Design, 18-Inch(Duct Opening Measurement), White Solid steel face and premium plated finish For floor application Volume control damper Listed product sizes refer to the duct opening measurements, not the register itself Actual length of item is 18-inches; inside duct opening measurement of item is 15-inches to accommodate the 1 -inch wide flanges on each end