True original battery. It avoids compatibility issues with the firmware of some devices that verify the originality of the battery pack. Although they are expensive, but having tested adaptable (ordered on Ebay in China in particular), this is the only whose capacity is real. The others are not even half of photos, as they are sold to be more powerful ... spot the mistake! So, better to invest in one true, only 3 false: well, you will avoid the risk of short circuits and other fire starts seen with some fakes.