A Russian Civil War aviation officers badge of the Special Manchurian Detachment bearing a unique design that holds paramount importance within the context of Manchuria and its association with Ataman Semenov. At its core, a double-headed eagle, an emblem of the Russian Empire, symbolizes the detachments link to Russian authority and dominion. The shield bearing the abbreviation OMO signifies the units distinct identity as the Special Manchurian Detachment, underscoring its specialized role. The Cyrillic initials AC are dedicated to Ataman Semenov (Grigory Semyonov), a prominent figure in the Russian Civil War in Siberia and the Russian Far East, particularly in Manchuria. With a screw back construction and original nut. Russian Civil War Badges and Military Memorabilia For Collectors.