Super practical product, which works perfectly. I highly recommend this product for those looking for a spare external battery for mobile phone, MP3, GPS, and other .... Very easy to use, indicator that shows the battery level, just one button to press to start charging, capable of charging 100% an iPhone several times without recharging the battery and at incredible speed (approx. 15% 20secondes in charge) !! Furthermore the cover provided with the battery is very convenient to carry around the battery without damaging it and this will not make it out of this world deserving the wrist strap (convenient for clumsy people). And the price is very affordable compared to other more expensive batteries is necessarily more efficient, never rely on this award as a guide to find the best product, and it is important to read the reviews to this an idea Product !! As ++++++++ happiness !!