You are looking at a Brass Hose McCann General Alarm Rotary Switch. This would have been painted while it was in use on a ship. The trouble it would take to keep this fully polished brass while on sea would be too much. After it was salvaged, the paint was stripped off so that you can enjoy the brass look in your home/restaurant.
This alarm has not been tested and is being sold in as-found condition.
Weight: 6.5 lbs.