Fits 16x16 Duct Opening Stamped Steel Return Air Grille Vent Cover Grille for Sidewall and Ceiling in White Surface Dimensions: 17.75"W X 17.75"H (16" W x 16" H Duct Opening) Built in magnets on each

Built in magnets on each side for easy installation

The Listed size 12'' X 12'' is for inside duct opening measurement

actual outsize overall dimensions is 13

This product has listed size 8''X 8'' is for duct opening measurement only

The Listed size 12"x8" is for inside duct opening measurement

Fits 16x16 Duct Opening Stamped Steel Return Air Grille Vent Cover Grille for Sidewall and Ceiling in White Surface Dimensions: 17.75"W X 17.75"H (16" W x 16" H Duct Opening) Built in magnets on eachThe Listed size 16"x16" is for inside duct opening measurement, actual outside dimension is 17. 75"x17. 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