This credit card is really a knife. Just putting that out there in case it wasn't coming across already. It's a 2.2mm thick, 85.6mm x 54mm CNC machined aluminum treat. Keep it in your wallet to impress your friends and gore your enemies!
We've been horrified and amazed by the CardSharp once before (in its first iteration), but the CardSharp 4 has a number of improvements. First of all the whole body is made of aluminum now, not just the 65mm blade, so you don't have to worry about plastic wearing out or cracking.
There's a new two-part safety lock (which seems like a really really good idea), a new rivet that holds the blade against the body, and an updated spring-loaded hinge to keep everything totally flat and on the same plane. Oh and the engineering on the origami-style folding is pretty cool (see video below). Unfortunately, the material upgrades seem to have brought the price up too, since the CardSharp used to be $23 and is now $90 . . . so that's a negative aspect. But presumably utility has improved? Is that a good thing? Who even knows anymore. [Bless This Stuff]