We have all heard about extended battery cases for IOS devices. I first heard about this one last year when I was beta testing IOS5 and was having battery life problems. I had heard about this case's little brother, the Mophi Juice Pack Air, but was not interested due to its smaller capacity and the fact that it did not fully charge your phone. This one's price is slightly higher at $99 when I bought it. However, I could not be happier. This case has extended the battery life of my phone by as much as 13 hours. The battery built into the case is a monster and can handle most anything. If you want a screen protector, this is not the case for you as the screen is unprotected. Taking the phone out of the case is easy to do if you want to change to an Otterbox case. All one has to do is take the top half off. THe phone simply slides out. There is no belt clip. A switch on the lower left side of the case turns the case's battery on or off. If you choose to do so, you can run your phone's built-in battery down first, then use the Juice Pack to charge it back up again. I do not do it that way; I use the case battery first, then when it dies, the IPhone's battery kicks in. However, this happens very rarely. If you are a very heavy GPS user, like certain friends of mine who play Waze, this case is the best investment you will ever make. It makes your phone slightly bulkier but it is not much bigger. You will not be able to use your IPhone's cable or the dock connector on the bottom without first taking the phone out of the case. Mophi compensates for this by putting a micro USB port in the case. It will come with a cable when you purchase it. Unlike the Air, this one allows you to sync as well as charge. A small drawback is that you will not be able to tell, if you are totally blind, how much juice is in the case's battery. The IPhone will say that it is "on A/C power" until the battery is dead or, if charging, it will say the usual prompts. Overall, I highly recommend this case for anyone who is looking to double the battery life of an IPhone 4 or 4S. This is considered by many to be the best extended battery out there, and for good reason. I am always telling blind friends who complain about phones dying to "get a Mophi."