They can be plot devices, its not really important since everyone will have one, but unless you spend a PP on it, yours can be taken away, destroyed, etc at whim by the GM,and be replaced next time you get to HQ, actually come to think of it, that is the same a as being a device regardless of paying points, so I'd just say everyone has one by default with no PP expenditure, and leave it at that, its simply not important to detail them too much.