24" x 24" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Insulated Line + Product Details Size - Compatible With Duct 7in Applications This sheet metal DDAG-A-1212

+ Product Details Size - 10"w X 24"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 42 5/8" width X 12 5/8" height -

actual front end outer dimensions are approximately 20 5/8" width X 32 5/8" height -

Looks like it was just waxed

+ Product Details Size – 24"w X 10"h is the size for the duct opening measurement only

24" x 24" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Insulated Line + Product Details Size Compatible With Duct 7in Applications This sheet metal DDAG A 1212 + Product Details Size 10"w X 24"h is the size for the duct opening measurement only actual front end outer dimensions are approximately 42 5 8" width X 12 5 8" height