The product is easy enough to use. It provides a very good extension of battery life and can suatain 2 cargers from around 30% up to full full battery power. Some may complain about the size but personally i like the heaveir feel of the phone when it's on. A big drawback for me is that the microphone port can't be used when the charger is on the phone. A small extension lead is provided to enable connection for your earphones to the case, but this is usesless as the extension does not even fit!! poor design here.