The combo of a beefy Exynos 7420 chipset, ultra-sharp Super AMOLED display, and speedy memory should hardly catch anyone by surprise. The setup debuted on Samsung Galaxy S6 and Galaxy S6 edge and is yet to have its performance matched by a rival.
Dropping the memory card slot and the removable battery from the Note5 specs surely raises eyebrows - both hardware features have been a staple for the product family since day one. Samsung appears confident that the bevy of available charging options will keep users happy.
It is original. Gsmarena have separate page for the Note5 Duos version. There are also another page with CDMA version. Search it in Gsmarena.