This is a custom-designed balisong, commonly known as a butterfly knife. The defining characteristic of this weapon is the fan-like opening of a freely pivoting blade, allowing rapid deployment or concealment. As a result, butterfly knives are outlawed in many countries.
It is still perfectly operational although the exterior surfaces have rusted.Some people don't need to hide how dirty their deeds are

This item only drops in states between 40% and 100% (Well-Worn to Battle-Scarred).