36"W X 4"H [Duct Opening] Linear Aluminum Clip-On Bar Return Air Grille [Outer Dimensions: 37.25"W x 5.25"H] Compatible With Duct 12in + Product Details Perfect Fit 4 X 12 Is CRFG2028 Width_14in

+ Product Details Perfect Fit & Easy Sizing - Designed for a 28" x 28" duct opening (measured at the opening)

+ Product Description Introducing our 10" x 14" or 14" x 10" Floor Grille - a reliable and durable air grill designed for exceptional performance and built to last

+ Product Details Perfect Fit & Easy Sizing - Designed for a 32" x 16" OR 16" x 32" duct opening (measured at the opening)

75" Width X 7

All Our Filter Are Tested Per ASHRAE-52

36"W X 4"H [Duct Opening] Linear Aluminum Clip On Bar Return Air Grille [Outer Dimensions: 37.25"W x 5.25"H] Compatible With Duct 12in + Product Details Perfect Fit 4 X 12 Is CRFG2028 Width_14in + Product Details Perfect Fit & Easy Sizing Designed for a 28" x 28" duct opening (measured at the opening) + Product Description Introducing our 10" x 14" or 14" x 10" Floor Grille a reliable and durable air grill designed for exceptional performance and built to last