BUTTERFLY KNIFE~ "Balisong" only in Philippines
BALISONG
"It is a folding pocket knife and also known as Balisong in the Philippines. It is sometimes called a Batangas knife, after the Tagalog province of Batangas in the Philippines, where it is traditionally made."
Parts of Balisong
Note: It is very dangerous and deadly weapon, if you have like this you better use it very carefully.