A knife is no good if you don't have it with you. The B-2 Nano Blade Knife is so small you have no excuse not carry it. Just 1.8 inches in length when closed, it's ideal for hooking to a keychain. It measures just over 3 inches open, with a split blade that offers both a flat and serrated edge, and thanks to lightweight but rugged 440C black stainless steel construction, it weighs less than an ounce. Available in black.