Once you opened your backpack with right click you are ready to access it. By using this Mod you are able to expand and upgrade the Minecraft Backpacks, there are currently four tiers: Basic, Iron, Gold, and Diamond. The Iron Backpacks Mod is perfect for those players who like to get and keep any item that they find while are mining, but they hate at the same time that the inventory doesn’t have enough space for all the items.