the "a" device is an award device of the united states military which is presented as an attachment to the american defense service medal and the air force overseas service ribbon. the "a" device is a bronze colored letter "a", pinned to the center of both awards. == atlantic device in world war ii == the american defense service medal was the first decoration to use the device and the award was originally known as the "atlantic device" and also as the "axis device". the "a" device was awarded to any member of the united states navy, united states marine corps, or united states coast guard who, while deployed to the atlantic ocean between june 22 and december 7, 1941, engaged in armed conflict, or potential armed conflict, with naval forces of the german kriegsmarine. those having done so were awarded the american defense service medal with "a" device, the intent being to recognize those who had participated in the "undeclared war" when the united states of america was assisting britain with war convoys and german u-boat interdiction.atlantic "a" device for american defense service medal - eligibility, naval historical center. accessed 4 january 2013. == usaf arctic device ==  the "a" device became obsolete after the second world war and did not appear again until the year 2002. at that time, the united states air force declared that the "a" device, now known as the "arctic device", would be awarded to those who had received the air force overseas short tour service ribbon for tours of duty north of the arctic circle.air force recognition programs > about devices, air force personnel public web services. accessed 4 january 2013. the device is not authorized for any other united states military decorations. note, however, that the two representations of the "a" device are different. the atlantic device does not have "feet" (sans-serif), but the arctic device does have serifs. although alaska has locations within the arctic circle, there are currently no bases within that region. as of february 8, 2007, only thule air base qualifies for this device. ==references==  
Awards_for_polar_exploration Devices_and_accouterments_of_United_States_military_awards Military_in_the_Arctic