I don't know the origin of this thing but guessing a heat vent over a floor furnace but most I've seen were bigger than this one. Appears to be in good condition, no visable cracks, breaks or repairs. Could sit on a radiator and give you a place to set your coffee cup.
Overall measurements are 28 3/4" long, 8 3/8" wide, would fit into a hole or cutout 28 x 7 1/2. The item "Antique long thin cast iron stove gratefloor furnace ventradiator topperother" is in sale since Saturday, May 8, 2021. This item is in the category "Collectibles\Kitchen & Home\Major Appliances & Bathroom Fixtures\Stoves". The seller is "sjg82003" and is located in Cheyenne, Wyoming. This item can be shipped to United States.