It is a product stamped Samsung, so no surprises, it's a great product, very well finished. It does not much thickened the phone, but allows for easier handling. In fact, the S4 tends to slip in his hands. The shell is soft rubber on the sides, therefore, a priori, it protects pretty good. I have not tested whether it protects well, my phone is not for the moment with not fallen, but it gives confidence. Combined with a glass film to my screen, I think I have my phone protected from all sides.
Little more, important: the price is great and attractive color are downright cool!