The Challenger 2 is the UK's main battle tank, and as such its key function is to destroy enemy tanks.
It has a good reputation for reliability, although it has experienced significant problems during military exercises in desert conditions.
Improvements to air filters have had to be undertaken to enable the tank to function properly in hot and sandy environments.
Built by Vickers Defence Systems, work started on the Challenger 2 in 1986 and the first units were delivered in 1994.
The new model has 150 improvements over its predecessor, the Challenger 1, which saw action in the Gulf War.
The UK has just under 400 Challenger 2s, some of which have been used in Bosnia and Kosovo.
The tank has a four man crew and an ability to target and destroy as many as eight targets a minute. Its fire control system is computerised and both the commander and gunner can locate enemy targets.
Its main weapon is a 120mm gun, which is capable of firing depleted uranium rounds.
It also uses armour piercing fin-stabilised discarding sabot (APFSDS) and high explosive squash head (HESH) shells.
The tank carries two machine guns, one for anti-aircraft fire and a second for attacking enemy troops. It also has smoke grenades.
In addition to its Advanced Armour Technology the Challenger 2 also has a nuclear, chemical and biological attack resistant compartment for the crew.
As long as they have rations the crew should be able to remain in the tank for the duration of any chemical attack.
The crew compartment has an air filtering system, as well as a heating and cooling system, it is also separated from ammunition for increased safety.
The Challenger 2 is powered by a Perkins 26.1 litre turbocharged diesel engine, CV12. This gives the Challenger an average cross country speed of 24 miles per hour (40 kph).