Operationally and geographically, the department is organized into five Borough Commands for each of the five Boroughs of New York City. Each Borough Command has a Borough Commander. For Manhattan, this commander is an Assistant Chief of Department (three stars), whereas each of the other four Borough Commanders are Deputy Assistant Chief's Of Department (two stars). Within those five Borough Commands exists nine firefighting Divisions, each headed by a Deputy Chief of Department (one star), who also has several Deputy Division Chiefs (Gold Eagle) to help run the division when the Deputy Chief is not on duty. Within each Division are four to seven Battalions, each led by a Battalion chief. The lead Battalion Chief for the battalion is the Battalion Commander (Silver Leaf) and the others are Battalion Chiefs (bronze Leaf). Each Battalion consists of three to eight firehouses and consists of approximately 180–200 firefighters and officers. Each firehouse consists of one to three fire companies. Each fire company is led by a Captain, who commands three lieutenants and twelve to twenty firefighters. There are currently four shifts of firefighters in each company. Tours can be either night tours (6 p. m. – 9 a. m. ) (15 to 16 hours) or day tours (9 a. m. – 6 p. m. )(10 hours). Under a swapping system called “mutuals”, most firefighters combine tours and work a 24-hour shift, followed by three days off. In one tour or shift, each company is commanded by a Lieutenant or the Captain and is made up of three to five firefighters, depending on the type of fire company/unit: an engine company is staffed by an officer and three to four firefighters; ladder companies, rescue companies and squad companies are staffed by an officer and five firefighters; a marine company is staffed by an officer and four firefighters; the hazardous materials (hazmat) company is staffed by an officer and six firefighters.