It is required to keep the receipt, the warranty card (if available) and the device itself with all its parts and accessories in order to voice claim in case it is necessary.
It is also recommended to keep the package, the wrappers – the ones for the accessories as well –, the Instruction Manual and other handouts (if available). Even though these last ones are not obligatory, in order to transact as smoothly as possible, we suggest you keep them as long as you may need them.