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 has been cold blued.This is the malbec of weapon design - Booth, Arms Dealer

This item only drops in states between 0% and 100% (Factory New to Battle-Scarred).