Staff Sergeant

Staff sergeant is a rank of non-commissioned officer used in several countries.
The originated when they were part of the staff of a British Army regiment. They were paid at that level rather than as a member of a battalion or company.
United States.
Staff Sergeant insignia
U.S. Army
Staff Sergeant insignia
U.S. Marine Corps
Staff Sergeant insignia
U.S. Air Force
Staff Sergeant (SSG) is the title of the E-6 rank in the U.S. Army and United States Marine Corps. It is just above Sergeant. It is just below Sergeant First Class in the U.S. Army or Gunnery Sergeant for the Marine Corps. It is a non-commissioned officer.
In the United States Air Force a Staff Sergeant (SSgt) is the title of an E-5. It ranks just above Senior Airman (SrA) and below Technical Sergeant (TSgt). It is the Air Force's first non-commissioned officer (NCO) rank.