WWI-1930?s, U.S ARMY, AIR SERVICE AVIATOR, SWEETHEART WING, 1/20 12K GF, VINTAGE Pinback, Hallmarked ?1/20 12K GF? This vintage U.S Army Air Service Aviator sweetheart wing is a must-have for any militaria collector. With a charming design and 1/20 12K gold-filled construction, this original piece from the WWI-1930s era is a true gem. The wing has not been modified and comes with a guarantee of authenticity. The country of origin is the United States. The theme of this piece is clear and would make a great addition to any militaria collection. The time period is well established as being from 1919-1938. This wing is an original piece and not a reproduction. A perfect piece for collectors of Original Period Items, 1919-38, Militaria, or Sweetheart Collectibles. ?1/20 12K GF" is a stamp you'll see on jewelry to indicate it's gold-filled. Here's a breakdown of the meaning: 1/20: This refers to the fraction of the total item weight that is gold. In this case, 1/20th of the item's weight is gold. So, for example, if a piece of jewelry weighs 10 grams, then 1/20th of that (0.5 grams) would be gold. 12K: This refers to the karat weight of the gold. Karat (abbreviated K) is a unit used to measure the purity of gold. 24K is pure gold, while lower karats indicate that the gold is mixed with other metals. In this case, 12K gold is 50% pure gold (12 parts out of 24). GF: This stands for "gold-filled." Gold-filled jewelry is made by pressure bonding a layer of gold to a core of a less expensive metal, such as brass. The gold layer must be at least 5% of the total weight of the item to be considered gold-filled by the Federal Trade Commission (FTC) in the US. So, "1/20 12K GF" means that the jewelry item is gold-filled, with a layer of 12K gold that constitutes 5% of the item's weight. The concept of "Sweetheart Wings" has a long standing tradition that dates all the way back to World War I. Upon graduating pilot training, servicemen would have a set of their wings turned into a pin or pendant by a local jeweler in order to give to their girlfriend, fiance, or wife before they went overseas. This custom grew even more popular during World War II, and the handcrafted jewelry became that much more impressive. International Buyers Please Note: We do not ship outside of the United States! No Exceptions. In addition, we will not ship to third party shippers or any other international shipping hubs such as International Shipping (EIS), EIS 110 INTERNATIONALE BLVD, GLENDALE HEIGHTS IL 60139-2080. If you place a bid, or make a purchase, we will cancel your bid, and or cancel your purchase! If you wish to make a purchase, you will have to find someone located within the United States to make the purchase for you. They would be responsible to send the package to you.