Complex sentence: The "M" device may be awarded for wear on the Armed Forces Reserve Medal to indicate mobilization in support of U.S. Military operations or contingencies designated by the Secretary of Defense.
Split into simpler sentences: The "M" Device, or Mobilization Device, is an United States military award device worn on the Armed Forces Reserve Medal. Wear of the device indicates mobilization in support of military operations or contingencies designated by the United States Secretary of Defense.