I have thought it was a mistake and that he had been delivered to me a chocolate bar. In fact it was indeed a battery for my phone, whose capacity is at least equivalent to the original one, if not more. I can only presume the duration in time, but it is clear that I will not buy more battery stamped samsung, over 90% are certainly copies of poor quality. Also and this is amazing, 2 or 3 weeks after my purchase I received an email DIRECT ANKER asking me if I was happy with my purchase and I remembered that it was guaranteed. HAT and congratulations. I will buy more than ANKER.