This sign shows the early shoulder sleeve insignia (SSI) adopted by the United States Navy during WW1. YOU WILL BE RECEIVING THIS SIGN ONLY, THE SET PICTURE IS FOR INFORMATIONAL PURPOSES. Complete set of signs that are shown in the third picture. They are separated by that thin black paper packaging so common in that era. Isorel was the precursor to Masonite, which was not patented until 1924 and did not begin mass production until 1929. This set was likely produced some time after the war as most units did not have an insignia until then. I have had speculation on what they could have been for and it has been suggested that they might have been for a veterans group, but I think that they might have been used more for design purposes, possibly by a company that was in the business of supplying the newly adopted insignia patches to the various units in the US Military. Each of the 85 signs in the set have a hole on the top and bottom of the sign which I believe would be used for mounting, and they appear to have been extensively used. I will be offering each sign for sale individually so please be sure to stay tuned to my other listings as these become available. United States Navy operations during World War I began on April 6, 1917, after the formal declaration of war on the German Empire. The American navy focused on countering enemy U-boats in the Atlantic Ocean and the Mediterranean Sea, while convoying men and supplies to France and Italy. This item is in the category “Collectibles\Militaria\WW I (1914-18)\Original Period Items\United States\Patches”. The seller is “laz-e-bid” and is located in this country: US. This item can be shipped worldwide.