Duralumin, an aluminum alloy used in airship frames and auto body panels, isn’t necessarily the first material springing to one’s mind when it comes to cell phones cases. But Japan-based Factron actually used it for its so-called FACTRON SIMPLEX, an iPhone case that lets you use a number of lenses (sold separately) with your iPhone camera.

The case is both designed and made in Japan and has “the same precision screws used in wristwatches”. It weighs 48g (the iPhone itself weighs 133g) and can be used both for the 3G and the 3GS.

The main selling point, apart from the nice design, is that the FACTRON SIMPLEX is lens-friendly, meaning it lets you mount several lenses and use them with your iPhone camera. And, what a coincidence, Factron sells those, too.

Factron sells the case in their international online store for $199.80. Scroll down the product page to see which lenses are compatible to it.