The M1 Abrams first entered US Army service in 1980. An improved version of the M1, the M1A1, was introduced in 1985. The M1A1 has the M256 120 mm smoothbore cannon, improved armor, and a CBRN protection system. The M1A2 is a further improvement of the M1A1 with a commander's independent thermal viewer and weapon station, position navigation equipment, digital data bus and a radio interface unit. Further upgrades include depleted uranium armor for all variants, a system overhaul that returns all A1s to like-new condition (M1A1 AIM), a digital enhancement package for the A1 (M1A1D), a commonality program to standardize parts between the U.S. Army and the Marine Corps (M1A1HC) and an electronic upgrade for the A2 (M1A2 SEP). During Operations Desert Shield and Desert Storm and for Bosnia, some M1A1s were modified with armor upgrades. The M1 can be equipped with mine plow and mine roller attachments if needed. Box contains 616 parts suitable to make any one of 5 variants:M1A1HA. M1A1HA with Track Width Mine Plow (TWMP). M1A1HA with Mine roller. M1A2 Abrams. M1 Panther II Mine Clearing Tank. Includes chain for the mine plough, film part for the periscopes, and 5 different markings, one for each variant.