10" x 4" Adjustable Blade Sidewall Ceiling Register Vent Cover Diffuser Heavy Duty Stamped Steel (Listed Size is for Duct Opening or Inside Measurement) The Listed size 14"x 8"

The Listed size 14"x 8" is for inside duct opening measurement

•Stamped face steel construction with 1/2" fin spacing for high air flow

All plastic construction with 1/2" fin spacing for high air flow with rust proof feature perfect for areas with high moisture

Individually packed with card board box for ultra protection

"outside" measurement is the surface you can see after the installation

10" x 4" Adjustable Blade Sidewall Ceiling Register Vent Cover Diffuser Heavy Duty Stamped Steel (Listed Size is for Duct Opening or Inside Measurement) The Listed size 14"x 8"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 10w X 4h is for duct opening measurement only, actual outsize overall dimensions is 12 wide by 6 high. If your duct opening size is 10 x 4, this is the right size and will fit in well. If you measure outside or surface size, you will