Tech21 uses D3O, which is some really cool orange putty which allows the user to put some on their finger and hammer it. Seriously, I have a video after the jump so you can see this for yourself.
What you see in the image here to the left is the Impact Mesh for the Galaxy S4. The Orange stuff that you see here is the 3DO putty. When this D3O is hit, it absorbs the force and disperses the energy away from the device. This means that the sides of your S4 are well protected.
The Impact Mesh Cases are able to cover the back of the phone, and they don’t make the phone look too bulky. You can find the cover by the Galaxy S4 here for about £29.99. Now let’s talk about the Impact Shield after the jump.
It has a BulletShield with a BASF protection interlayer, and it is thin with an optimum touch sensitivity. The best part is that the screen protector doesn’t add more volume to the phone.
You can get these Impact Shields on the Tech 21 site for £19.99 for various smartphones. That previous link was for iPhone 5.