Wing is the name of Sydney’s melee knife. It’s a butterfly model made by Berger, which she never leaves home without as it has saved her life more times than she can count. Those who know her also know the story of how she got it from another gang leader. Got it from his throat. So people seldom mess with her when she whips it out. Wing is a nifty little thing and Sydney loves showing off her skills. And everybody knows that when Wing starts flapping - chaos will come.
The Wing's manufacturer Berger is a parody of Gerber Legendary Blades. This is rather unusual, however, since GLB does not make butterfly knives in reality as it is a well-known manufacturer of survival and utility knives instead of trick and/or concealable personal defense ones.
The Wing strangely "unlocks" twice. This does not seem to have any effect.