The Ballistic Shell for the iPhone 4 and 4S protects the phone with a soft silicon interior and a hard shell on the outside.
I find that the case is very protective with the thick silicon and shell barriers. The silicon provides easy access to your buttons that are not to hard to press. There are cut outs for all the headphone jack, vibration switch, dock connector, speaker, and microphones. The camera cut-out does not cast a reflection on the flash which provides a disturbance free image.
I believe that this case is a great way to provide maximum protection without huge bulk. Although this case does not have a built in screen protector, it does have a large lip to keep the front away from a surface.
I would recommend this case to users with an iPhone 4 or iPhone 4S.