Used, spent shell casing, non-explosive, 105MM cartridge blank for M395 Howitzer, 6" tall, 4.75" base diameter, aluminum.
Although they look like brass they are not. They are aluminum. They can still be polished and work great as pen holder on a desk.
I had an ash tray made from one when I was in the service (lost it a long time ago). Saw this and knew I wanted to have one made again.
Just as described.