[1] The blade of a butterfly sword is roughly as long as a human forearm, which allows easy concealment inside loose sleeves or boots,[citation needed] and allows greater maneuverability when spinning and rotating during close-quarters fighting.

The butterfly sword has a small crossguard to protect the hands of the wielder, similar to that of a sai, which can also be used to block or hook an opponent's weapon.

In some versions the crossguard is enlarged offering a second handhold, held in this position the swords can be manipulated in a manner akin to a pair of tonfa.

[citation needed] The blade from the midpoint down is left blunt so that it can be used to deliver non-lethal strikes and to block without damaging the sharpened edge.

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.

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.