Old Vintage Brass Funeral Mausoleum Vent Plaque Maker Goldstein Brooklyn NY Cemetery.
This is not a new item. It was used and and reclaimed after a mausoleum rebuild or move.
Look at photos for condition.
These rarely come up for sale.
Original makers advertised on old brass.
8 inches long x 2 1/2 high x 2 1/2 deep