Senior Enlisted Advisor to the Chairman is a military position within the United States Department of Defense and is the most senior noncommissioned or petty officer overall in the United States Armed Forces. The SEAC is appointed by the Chairman of the Joint Chiefs of Staff to serve as a spokesperson to address the issues of enlisted personnel to the highest positions in the Department of Defense. As such the SEAC is the senior enlisted advisor to the Chairman of the Joint Chiefs of Staff, and serves at the pleasure of the Secretary of Defense. The SEAC's exact duties vary, depending on the Chairman, though he generally devotes much time traveling throughout the Department of Defense observing training and communicating to service members and their families. The normal tour of assignment is four years, which runs concurrently with the Chairman. The first member to hold this post was William Gainey. On 11 December 2015, the Chairman of the Joint Chiefs of Staff, General Joseph Dunford, administered the Oath of Office to CSM John W. Troxell, USA. Troxell becomes only the third member and second soldier to hold the office.