Kompell Aire RV and Home White Stamped Steel Floor Diffuser/Register with Damper 8" X 4" (Duct Opening Size) Outside Dimension 9.6"x 5.6"

First thing to know about size selection: take the vent cover off the wall or ceiling. Measure the duct opening where the vent can fit in. Use the measurement to determine right size to buy. This product has listed size 8“w X 4”h is for duct opening measurement only, actual outsize overall dimensions is 9.6” wide by 5.6” high. If your duct opening size is 8” x 4”, this is the right size and will fit in well. If you measure outside or surface size, you will get a large one and it will not fit.

• The Listed size 8"x 4" is for inside duct opening measurement, actual outside dimension is 9.6" X 5.6"
• Stamped face steel construction with 1/2" fin spacing for high air flow
• One way air flow deflection design
• Multi-shutter damper with easy handle to adjust desired amount of air flow
• Individually shrink wrapped with cardboard pad in the back for extra protection