Butterfly Knives
Butterfly knives, or balisong, otherwise known as a butterfly knife or a Batangas knife or sometimes called Bente Nueve, is a folding pocket knife with two handles counter-rotating around the tang such that, when closed, the blade is concealed within grooves in the handles. In the hands of a trained user, the knife blade can be brought to bear quickly using one hand. Manipulations, called flipping, are performed for art or amusement.