This is a very nice copper and brass nautical air horn removed from a ship destined for scrap at the shipbreaking yard.  Measures 13″ long.  The copper bell end measures about 5 3/4 inches in diameter and is mounted to a brass base.  The brass base has two screw holes that are about 5 1/8 inches on center. This horn is unmarked.  In working condition.  It has a bit of weathering from use on a real boat.