The product is suitable tares well to what I was looking for, that is to say to ask my phone to recharge, where to put a backup battery to recharge. Plus: there is a extra battery to S4 delivered (I did not understand) Cons: Very short USB cable (you can connect this device to a laptop, not a tower) / forced to open my "flip cover" for loading if it is too large and no place to connect the S4.