Product details:

Faceplate dimensions measure 21 13/16" x 31 13/16". The approximate thickness of the faceplate is 3/16 inch and drops into the hole opening approximately 3/4 inch. This cold air return cover is the rigid steel construction you'll want for your large 20 x 30 inch floor hole opening. The commercial grade floor vent has the strength to hold up in heavy foot traffic areas. You can also use the classic style cold air return cover in residential areas. This commercial grade floor vent cover is finished in a medium tan color and has a smooth surface. This is a drop-in style installation cold air return cover. Just place over the 20 x 30 inch floor hole opening. The outside surrounding lip will hold the commercial grade floor vent in place. There is a free air flow area averaging 75%.