Backpacks

To open backpack:

1.  Wear it!

2.  Right-click on the key

Key - Used to open the backpacks.

Small - Smallest of the backpacks. Size of normal chest.

Large - A pretty dang large backpack. Size of double chest. 

Linked - A backpack capable of interfacing with many different types of containers: chest, double chests, furnaces, etc. It works at any distance, even across dimensions. It is the ultimate backpack.

Combined - A backpack which can store multiple backpacks for quick use. 

Craft - A crafting table in a backpack.

Ender - An enderchest in a backpack.

Furnace - A first of its kind portable furnace.