Pip-Boy-3000: As of right now, the pipboy functions as an extra eight slots of inventory which can hold any item, besides another pipboy. Right click to open the inventory. Multiple pipboys can exist at the same time and ARE NOT player specific. This means, on a server, if you place something in your pipboy and give it to someone else, they will receive those items.
Empty Syringe: The empty syringe is used to craft many of the chems found in this mod.
Bottle Cap: The currency of the Fallout universe. However, no merchants will accept these as of right now.
Leather Belt: Currently only used in the super stimpak recipe