Truaire C160MBP 04X08(Duct Opening Measurements) Decorative Floor Grille 4-Inch by 8-Inch Plastic Floor Diffuser, Composite Collection, Golden Sand Finish Rust proof ABS resin Model Size Indicates Duct Opening Measurements not Wall Opening Measurements. Dishwasher safe Great for high humidity area The actual face size is 9.5-inch in width and 5.5-inch in height.