Leopard 2A4 with reactive armor Kontakt 1. Kontact 1 is a first-generation dynamic complex developed in 1982 by the development of the Research Institute of Steel to increase the protection of armored vehicles from cumulative ammunition and anti-tank missiles. The security element has an index of 4C20. Leopard 2A4 is a German main battle tank. The fourth modernization of the Leopard 2 tank. Produced from 1985 to 1992. As of 2023, the tank has been withdrawn from service in Germany, but is still in service in a number of other countries.