20" X 20" Steel Return Air Filter Grille for 1" Filter - Fixed Hinged - [Outer Dimensions: 22 5/8" X 22 5/8"] sidewall 3 * Insulation density is

3 * Insulation density is 30kgs/CBM = 0

Actual Filter Size – 29 3/4"w x 23 3/4" x 1"

Complies with industry standards of USA: ASTM D-882

+ Product Details Size - 36"w X 4"h is the size for the duct opening measurement only

actual front end outer dimensions are approximately 14 5/8" width X 32 5/8" height

20" X 20" Steel Return Air Filter Grille for 1" Filter - Fixed Hinged - [Outer Dimensions: 22 5/8" X 22 5/8"] sidewall 3 * Insulation density is+ Product Details Size 20"w X 20"h is the size for the duct opening measurement only, actual front end outer dimensions are approximately 22 5 8" width X 22 5 8" height. High Quality high quality solid stamped steel with counter sunk screw holes (screws included) and no sharp edges Installation Location Ceiling Design Fixed hinged for easy filter change & cleaning uses a 1" thick filter. Our filter grille latch is easy to use on your fingers and