tanks into a single, all around type. They are also the most expensive to mass-produce. A main battle tank is distinguished by its high level of firepower, mobility and armour protection relative to other vehicles of its era. It can cross comparatively rough terrain at high speeds, but its heavy-dependency on fuel, maintenance, and ammunition makes it logistically demanding. It has the heaviest armour of any AFVs on the battlefield, and carries a powerful precision-guided munition weapon systems that may be able to engage a wide variety of both ground targets and air targets. Despite significant advances in anti-tank warfare, it still remains the most versatile and fearsome land-based weapon-systems of the 21st-century, valued for its shock action and high survivability. Tankette A tankette is a tracked armed and armoured vehicle resembling a small "ultra-light tank" or "super-light tank" roughly the size of a car, mainly intended for light infantry support or scouting. They were one or two-man vehicles armed with a machine gun. Colloquially it may also simply mean a "small tank". Tankettes were designed and built by several nations between the 1920s and 1940s following the British Carden Loyd tankette which was a successful implementation of "one man tank" ideas from Giffard Le Quesne Martel. They were very popular with smaller countries. Some saw some combat (with limited success) in World War II. However, the vulnerability of their light armour eventually caused the concept to be abandoned. However, the German Army uses a modern design of air-transportable armoured weapons carriers, the Wiesel AWC, which resembles the concept of a tankette. Super-heavy tank The term "super-heavy tank" has been used to describe armoured fighting vehicles of extreme size, generally over 75 tonnes. Programs have been initiated on several occasions with the aim of creating an invincible siegeworks/breakthrough vehicle for penetrating enemy formations and fortifications without fear of being destroyed in combat. Examples were designed in World War I and World War II (such as the Panzer VIII Maus), along with a few in the Cold War. However, few working prototypes were built and there are no clear evidence any of these vehicles saw combat, as their immense size would have made most designs impractical. Missile tank A missile tank is a tank fulfilling the role of a main battle tank, but using only anti-tank surface-to-surface missiles for main armament. Several nations have experimented with prototypes, notably the Soviet Union