Coming to a knife fight with nothing but your wallet is a silly idea.  Unless you’ve got the Card Sharp, a folding knife that’s literally shaped and sized like a regular credit card.
Made by Iain Sinclair, the novelty blade measures just 2mm thick, allowing you to slip it into your wallet’s card pocket, along with your zero balance ATMs and maxed-out credit cards. It’s ultra-light at 13 grams, too, adding neither much bulk nor heft to your standard billfold.
From its rectangular shape, the Card Sharp requires just three folds to transform into a functional knife. The 65mm blade is made from high-quality, rust-free stainless steel, boasting surgical-grade construction that ensures long-lasting sharpness.  You can get it in either a natural stainless steel color or a black Teflon-coated finish.
The knife’s body is made from black polypropylene plastic, with a classy-looking etched label adorning it.  A built-in sheath folds just over the serrated surface during card mode, keeping you from accidentally hurting yourself on the sharp edge when pulling it out of your wallet. There are no hinged parts anywhere on the folding body, either, so you can wash caked blood off all you want without inviting rust.
The Card Sharp is available for pre-order now, priced at £7.50 (around $12).  When it begins shipping in January, that price doubles to £15.
[Card Sharp , Via]