I have a 1994 Mercury Cougar and I was going through my car and found this weird key that says "MASTER" on it, it has symetrical tumblers on both sides, at first I thought it was something the previous left accidentally in the car, but I was on ebay and noticed a car with this exact same key with the owner's manual. My car didn't have an owners manual so I couldn't look it up. Does anybody know what its for?