Since 1984 the main armament of the two variants M1A consists of a derivative of the Rheinmetall 120 mm gun, called M256A1. The first models, equipped with the 105mm cannon were removed from service. The secondary armament consists of two 7.62 mm machine guns, plus a 12.7mm machine gun that can be operated from inside the vehicle on most versions. The machine also has an NBC protection system, a laser rangefinder, a gyro-stabilized gun and a shooting system controlled by a dedicated computer. The M1A1 Abrams is distinguished by its Rheinmetall 120 mm gun of German origin, which equips also the Leopard tank 2. The newest, the M1A2 Abrams, is given a new fire control system (rotary thermal sight, an independent weapon station for the tank commander) and a new board computer (a data acquisition interface and communications, navigation and positioning equipment). This behemoth of about 61 tonnes is led by a crew of 4 men and can mainly darken at the speed of 72 km / h, and a distance of 465 km.