Currently shipping model is 750GB and this is maximum size you can buy at this time. If you open/disassemble the NVS yourself, it will be void manufacturer warranty. If I were you, I would not attempt of changing the internal drive myself.
Answer by NextoDI2013-05-16
NextoDI use 7200rpm HDD to guarantee fast back-up speed.
please don't replacement internal HDD yourself.
Warranty void if the Main unit is disassembled.