I received the product with the batteries already placed (= repackaged product) He did not like the synchronized with the Galaxy S5. I had the idea to buy Auchan 1000mA rechargeable battery. perfect synchronization twice and forced to reload. I reboot every two suddenly use and no problem. the rest all is ok good good presentation interface. Open API for programming apps if needed. after considering the price I think it is better to buy a range dessus.c'est irritating to recharge every two uses.