Since its introduction in 1979, the Leopard 2 main battle tank has been continuously adapted to the requirements through retrofitting due to changing threat situations and technological advances, especially in the field of electronics. The A7 version is currently establishing itself as the new standard for modernizing main battle tanks.

The first standard is the A4 version, which the manufacturer Krauss-Maffei Wegmann (KMW) delivered up to 1992. The main battle tanks in the troops were converted to this configuration. With the "Mannheim Configuration" began the first increase in combat effectiveness with reinforced armor, new optronics and a new weapon system with electric turret drive. From 1995, 350 main battle tanks were upgraded to the A5 and from 2001, 225 A4 and A5 were converted to the A6 version by fitting the 120mm L55.