Armed Forces Reserve Medal National Guard is a service medal of the United States Armed Forces that has existed since 1950. The medal recognizes service performed by members of the National Guard after completing a total of ten years service. If the medal is awarded for periods of service, it is accompanied by an hourglass device. Depending on the length of service, a bronze, silver, gold, or bronze and gold hourglass are worn on the suspension ribbon. If the medal is awarded in connection with a mobilization, it is accompanied by an “M” device.