A Balisong is a type of small knife whose handle doubles as a blade cover. The handle is made in two halves that rotate independently to cover the blade. This type of knife originates from the Philippines and is quite popular in the Southeast Asia, both as a handy day-to-day tool and as a weapon, but owing to its compact size, concealable nature and ability to speed-deploy, it is legally restricted in many countries. Blunt versions are often sold for training purposes.
A Balisong can be swiftly deployed by flipping out the blade when held by a trained user. This technique is also displayed onscreen by Alicia in Do Not Disturb.