From the NAM miniature missile page,
When heavier, more specialized powered armorsuits began moving into active circulation for Nepleslia's Star Military, a newer variation of the minimissile launcher system came in to take advantage of the increased weight capacity. The FIRE was the first to make use of the Extended Rack System; a much larger version of the Rapid Launcher system which was mounted on the FIRE's unique powered rear hardpoints. These racks, which were roughly the size of large storage lockers, were able to store and launch over twice as many missiles as its smaller cousin as the cost of a heftier size and weight. Not all armorsuits in circulation are able to make use of the Extended Rack System, and they must be requested during gear loading before missions.
Minimissiles are typically about the size of an 8 oz tin can, with all systems included. Because of the small size, minimissiles are suggested for use in close or medium range combat, as propellant stored inside minimissiles do not last very long.
The Extended Rack Missile System is a modular piece of equipment, capable of storing differing amounts of the missiles it can carry- Each system is composed of six cells. Each cell is capable of firing every missile in it simultaneously or at a rate determined by the controller. Each cell is capable of storing the following amount of missiles: