First developed by Perfecto de Leon in 1905 the balisong (also known as the Batangas knife or more commonly the Butterfly knife) is a knife coming from the Batangas province Philippines. It is said it can be opened as fast, if not faster, than a normal switchblade. Even though it has no springs.

The shape of a balisong is not easy to describe with words. Think of it as a Leatherman with no tools, a blade were the pliers would be, and it opens and closes far easier. Some also have latches in the ends of the handles that lock into position whenever the balisong is opened or closed. Some users complain that these latches can get in the way and sometimes chip the blade while closing. The standard overall length of a balisong is 29 centimeters, though some balisongs are custom made in lengths of up to two feet.

Balisong were commonly used by nasty ninja street gangs in many 70's kung-fu movies (Even though they come from the Philippines). Unfortunately, this has caused a lot of people to link the balisong with bad guys.

Balisong manufacture is divided into several specialized areas. The blacksmith who forges the blade, someone to make the rough handle, another to build the latches, and several more to decorate the handle and assemble the finished parts.