Assault 'Mechs are the heaviest regular class of BattleMechs, weighing in between 80 and 100 tons. Some of these huge 'Mechs can mount up to 50 tons of weapons as well as very thick armor protection. They can project tremendous firepower, and perform best as the spearhead of frontal assaults or in defending entrenched positions. The trade-off is in speed and maneuverability, as assault 'Mechs are generally very slow. As such, they often require friendly units to protect them from being outmaneuvered. Assault 'Mechs are typically used as command units, heavy assault platforms, and in fire-support roles, but due to their prohibitive costs and limited production, they actually make up only a small fraction of all BattleMechs.