Several years ago, designer Iain Sinclair launched the Cardsharp, a razor-sharp stainless steel knife folded into a credit card-shaped package. The knife combined real-world function with sleek, aesthetic design. Late last year, Sinclair updated the knife into the Cardsharp 2.

An evolutionary update, version 2.0 of the Cardsharp includes a stiffer polypropylene build and a child-proof safety lock. The knife packs 2.5 inches (6.5 cm) of stainless steel cutting surface into its own card-like sheath. A series of three folds is all it takes to turn the device from card to knife.

While the Cardsharp 2 doesn't offer as much utility as a multi-tool, it's a featherlight (13 gram) knife that's easy to transport anywhere. The knife can slide easily into a wallet, pocket or gear bag, and the blade locks into its sheath so it won't open accidentally. Sinclair says that the knife is less than a tenth the weight of a Stanley utility knife and about a seventh the weight of a Leatherman knife.

It's not too difficult to imagine uses for a thin, razor-sharp go-anywhere knife. The Sinclair firm says that it's useful for everything from emergency wilderness survival to arts and crafts. It can be customized with silk screen printing or laser engraving for use as a gift or promotion. It retails for US$25.

The video shows how easily the knife transforms.

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