Fits 20x8 Duct Opening Stamped Steel Return Air Grille Vent Cover Grille for Sidewall and Ceiling in White Surface Dimensions: 21.75"W X 9.75"H (20" W x 8" H Duct Opening)The Listed size 20"x8" is for inside duct opening measurement, actual outside dimension is 21. 75"x9. 75" Stamped Face Steel Construction with 1 2" fin spacing for high air flow applications. Screws are included for easy installation White Powder coating with matte finish Individually packed with cardboard box for ultra protection

Duct opening – a hole that holds the duct neck to allow air to come out from HVAC system

it refers to the size of the "tongue"  so that it will fit in a 8"x8" hole

Four Way Air Flow deflection Design

Working temperature ranges 40-degree F to 150-degree F

Actual outside measurement is 14" x 8"

The listed size 14" x 6" is for the inside duct opening measurement

and hassle-free setup

• Durable Construction – Made with corrugated stainless steel for superior strength

The protective yellow epoxy coating covers the entire length of the connector

15" long heavy duty steel construction with decor oil brunched powder coating finish

Universal connector fits all washing machines

The Listed size 18"x18" is for inside duct opening measurement