In Ancient China, when they were used in the extended form, they could be used in the same conditions as other bladed weapons such as the Sword or the Sabre, and yet when they were inverted, the distance was reduced and greater effectiveness was achieved in more places. closed in which the sword moved with more difficulty.
One of the characteristics of the Butterfly Knives is that it has an "S" that forms a protection and that extends the length of the handle, to cover several more centimeters from the tip of the knife. Also, the portion that covers the handle protects the fingers of the person holding the Knife from cuts or injuries thrown by another weapon in combat.
The hook portion of the guard, which protrudes several inches above the blade, allows the Kung-Fu practitioner to reverse the Knife with a quick flick of the thumb. In this inverted position, the knives block other weapons or are used to fight in close quarters where the martial artist does not have the ability to use their Knives to their full extent.