One minute the Mantis Bottleneck Butterfly Knife is an innocent-looking bottle opener with a pocket clip, and the next (after some skillful flipping action) it’s a downright frightening 2″ open blade that also happens to be legal in all 50 states. Made entirely from stainless steel, weighing in at 3 ounces, and 100% awesome.

Pick one up at Amazon in bead blasted (pictured), black or silver – 33$. [source]