Erco ball turret on a Consolidated PB4Y-2 Privateer, Pima Air & Space Museum (photo: Paul Woodford) | Air and space museum, Aerospace museum, Republic gunship
LEGO Part 44359 Cylinder Hemisphere 3 x 3 Ball Turret [Light Bluish Gray] (6249938, 4529550) | iBricktoys: LEGO shop guide and database