By the start of World War I, the 77 mm had become the standard German weapon, and came mounted on a large traverse that could be easily picked up on a wagon for movement. Krupp 75 mm guns were supplied with an optical sighting system that improved their capabilities. The German Army also adapted a revolving cannon that came to be known to Allied fliers as the "flaming onion" from the shells in flight. This gun had five barrels that quickly launched a series of 37 mm artillery shells.