This is a vintage wall hydrant plate. It looks to be made of brass and it weighs in at 5 lbs 7 oz and measures 11" by 12" and the center opening diameter is 4 1/2.
It is in nice condition with some age type finish wear on it and I show a number of photos. This item is in the category "Collectibles\Historical Memorabilia\Firefighting & Rescue\Hoses & Nozzles". The seller is "redding1" and is located in this country: US.