Inventories are categorised into four Major groups. Weapons, Armors, Vehicles and Special. They can be bought in for Cash or Diamond and can be won doing Missions and Special Assignments.
There are special inventory rewards for Tournament toppers and Some available from the Gang Arsenal.
The significance of MOBS is here. Every mob member can carry the best Inventory from each of these categories.The more the number of mercs and Mobs more the Inventory you can carry to each fight. The maximum number is restricted as <code>5 * Level</code> for Mobs and <code>3 * Level</code> for Mercs.
Bosses who join you as Mercs and the special Mercs can carry a significant amount of Armory with them than the usual Mob.