Apple's leather-finish iPhone 5S case will protect your phone from everyday bumps and scratches. If the way you live and work means you give your phone a harder time, then Tech21's €29.99 Impact Shell Case promises to absorb more punishment.
There are two ways to build a protective shell around a smartphone. You can build something that's strong and tough to effectively armour-plate the device or you can make something software and squishy to absorb the blows. The first approach might stop bullets, but it won't protect the iPhone's glass from cracking if you drop it.
Tech21 has taken the second approach. It's Impact Shell case wraps the iPhone 5S in a soft Polymer material it calls D3O. The company says the military uses D3O to protect devices in battle conditions and in high impact sports material.
Tech21's marketing says this about D3O: "In everyday use the molecules flow freely, but on shock or impact they lock together absorbing the force and spreading the shock evenly across the surface".
Well that's the theory. In practice the Impact Shell fits around the side and back of the iPhone 5S with holes in all the right places, including one for the camera and buttons over the phone's volume controls. The edges extend a millimetre or two higher at the front giving the screen a little extra protection should you drop the phone face down on to a flat surface.
The case is a little bigger than Apple's iPhone 5S case and weighs a little more at 26g compared with Apple's 13g.
I don't have the budget to drop iPhones on concrete to test the Impact Shell's effectiveness, but I did manage to drop the protected phone a couple of times by accident and can report there's no visible damage.
There are negatives. The Shell Case isn't what I'd call ugly, but it does detract from Apple's beautiful physical design. On a more practical note, the phone's buttons and controls are a little harder to use when the Shell Case is on. It also feels a little clammy in the hand, but that goes once it warms up. The case is a little easier to grip than the naked iPhone 5S.