... The shell shall be designed for the iPhone 4?

The shell is extremely thin what it is on the one hand practically since hardly aufällt that you attached to the iPhone.
However, by a protective sheath can be no question ... except perhaps against scratches. A fall would never survive the iPhone.
Since my old Bumper from Apple is clearly better.

What's much more tragic .... the shell is so designed that you slipped permanently from iPhone and drops.
The holes are not provided properly. You are indeed serve up some buttons, but they are partly covered halfway through the shell.

Actually, I never had problems with Belkin and bought the shell because of the name and the proven quality, but this protective sheath
beneath contempt and nothing but a waste of money!