Essential for S4: handy with its window. By opening the flip, "wakes up" the display and you can answer a call without having to open it. Moreover, it did not increase the smartphone as it happens with conventional silicone protections: to Replace the back cover of origin by this set consists of a shell and flap. It is elegant yet very discreet and fully protects the screen. Only flat, the sides of the S4 are not protected in case of fall ... One can even insert the S4 with this "case" in a cuff to run smoothly. By cons, if you must ride your S4 on a bike with a suitable support, it will certainly put the original shell (I am in this case). And with the Samsung refund offers (until 30/09/2014), this case comes to my 4: that's why I put 5 stars because if the normal price is a little high (though on Amazon, it is already almost half price compared to some vendors). Highly recommended.