The M1 Abrams is an American third-generation main battle tank named for General Creighton Abrams. Highly mobile, designed for modern armored ground warfare, the M1 is well armed and heavily armored. Notable features include a powerful AGT1500 multifuel turbine engine, sophisticated composite armor, and separate ammunition storage in a blow-out compartment for crew safety. Weighing nearly 68 short tons (almost 62 metric tons), it is one of the heaviest main battle tanks in service.
The M1 Abrams entered U.S. service in 1980, ultimately replacing the M60 tank. The M1 is the main battle tank of the United States Army and Marine Corps, and is also used by the armies of Egypt, Kuwait, Saudi Arabia, Australia, and Iraq.
Three main versions of the M1 Abrams have been deployed, the M1, M1A1, and M1A2, incorporating improved armament, protection, and electronics. These improvements and other upgrades to in-service tanks have allowed this long-serving vehicle to remain in front-line service. In addition, development of the improved M1A3 version was first publicly disclosed in 2009. Extensive improvements have been implemented to the latest M1A2 SEPv3 version.
Source: Wikipedia, "M1 Abrams", available under the CC-BY-SA License.