Choy Li Fut. In Wing Chun, one notable aspect of butterfly sword combat is that its principles are the basis for all other weaponry. In theory, any object that can be held in the hands of a Wing Chun practitioner will follow the same basic principles of movement as the butterfly swords. This is because the use of butterfly swords is simply an extension of empty-handed combat. The design of the weapon, including the quillon (crossguard) shape, blade profile and blade length, are specific to each style of martial arts, the precise lineage, and individual. For example, some martial arts lineages flip the butterfly swords between the forward and reverse grip like a Sai, and consequently need a quillon that will fit the hand during a reverse grip. Some lineages trap the opponent's staff or blade between the quillon and spine, and they need a longer quillon closer and more parallel to the spine than would fit a hand after flipping. Some schools like a hybrid quillon design that is adequate for both flipping and trapping, but optimal for neither. Some butterfly swords had a long narrow blade that emphasized stabbing. While a deadly stabbing blade with a sharpened point—known as "Red Boat" knives—was used by Chinese revolutionaries in the Wing Chun lineage, modern Wing Chun practitioners tend to prefer a blade profile with a wider belly that emphasizes chopping and slashing. Wing Chun lore attributes this to the desire of Monks to maim rather than kill. These knives generally have a quarter circle style tip suitable only for chopping/slashing and not stabbing, or a shallower curve to a more pointed tip that will accommodate both. The appropriate length of the blade is a combination of the lineage and individual. For a Hung Gar stylist, the length should be a few inches past the elbow when the knife is held in a reverse grip. Wing Chun schools that use techniques which twirl the knives inside the arm need a reverse grip blade length based on the distance to the interior of the bicep. Other Wing Chun schools measure to the outside of the bicep. Popular culture In Heroes of the East, two butterfly swords were among the weapons used by Ho Tao. Two butterfly swords were used by Monzo Ram, a Triceraton gladiator on the Teenage Mutant Ninja Turtles episode "Turtles in Space – Part 4: The Arena". Ip Man