Balisong Knives

Whether it's because they're illegal, because of their swift deployment or due to their exotic nature, Balisong knives, also known as butterfly knives, have become black market items in much of North America due to perceived gang relations.

Traditional symbols of both spirituality and class, these Filipino-originated knives can be as beautiful as they are fun to flip. Trainers [knives with blunt blades that cannot be sharpened] are readily available, but few reach such a high quality as some true custom balisongs.

However, if you're mainly interested in the form because of it's structural integrity, Cold Steel, a knife company, produces a slip-joint version of a butterfly knife. Due to the inability to open the knife with centrifugal force, they're 100% legal where knives of a similar length are legal as well.