There are times when having a knife can come in handy. However, not all of us want something like a pocket knife sitting in our front pockets all of the time. Sure, you can get a little one that attaches to your keychain, but that’s hardly going to be effective. You’d be much better off getting a CardSharp.

This is easily one of the coolest knives I’ve seen. When not in use, it has a rectangle shape and is roughly the size of a credit card. This allows you to store it in your wallet, where it will be completely unobtrusive. With a few simple folds, you’ll have yourself a very functional 2.5-inch stainless steel blade. Don’t worry though, it locks open and closed, so you don’t have to worry about it accidentally folding or unfolding when you don’t want it to. At just $25, this seems like a good buy for anyone who wants to keep a small knife on hand. Just remember to take it out of your wallet before you head to the airport.