Challenger is a development of the Shir 2 MBT originally built to meet the requirements of Iran. This tank has Chobham armor in its hull and turret, which gives a high degree of protection against both kinetic and chemical energy attack. The 120mm L11A5 rifled gun is identical to Chieftain's. A 7.62mm MG is mounted coaxial to left of main armament and a second on the commander's cupola.