A divisional unit in the United States Army typically consists of 17,000 to 21,000 soldiers, but can grow up to 35,000 to 40,000 with attached support units during operations, and are commanded by a major general. Two divisions usually form a corps and each division consists of three maneuver brigades, an aviation brigade, an engineer brigade, and division artillery (latter two excluded from divisional structure as of 2007), along with a number of smaller specialized units. In 2014, divisional artillery (DIVARTY) organizations began to re-appear, with some fires brigades reorganizing to fill this role.