Gadgetwise: The AL13 Is an Aluminum Case With No Screws to Lose

The AL13 aluminum case from Designed by M uses a sliding frame to lock an iPhone into place.

Aluminum cases for the iPhone tend to be light and durable but are assembled with minuscule screws that are easy to lose or snap.

The AL13 aluminum case from Designed by M avoids that problem by using a sliding frame to lock the iPhone into place.

The AL13, which began as a Kickstarter project, is a bumper-style case. That means the hard part wraps around the edge of the phone, and leaves the front and back unobstructed, like the plastic bumper that Apple supplied with the iPhone 4. The front and back are covered in a protective film that comes with the AL13 case comes with a protective film for the front and back of the phone.

The case is very easy to assemble. After you apply the films, you just slide the rear frame off the bumper. It glides along a track like a drawer. Push the phone into the bumper then slide the frame back into place (which can take a little fiddling).

It looks like good protection against scratches and dings, but because there is minimal shock-absorbing material inside the bumper, I wonder how much protection there would be against the concussion of a drop.

The bumper, which is anodized aircraft aluminum, is made in purple, blue, fuchsia, white and gunmetal gray.

The AL13 is available online from Designed by M, at $80 for the iPhone 4 or 5.