This is the classic "Trick Knife" made by Imperial (has patent number but not Imperial stamp) and blade is etched with Certified advertising. The blade is locked closed by an interior mechanism and can only be opened by holding it tip up and pushing in on the blade, then it opens manually - a must for the collection to show off and give your friends a challenge and a laugh! Blade does not lock open. The blade is used and has been sharpened, but it is in good usable condition.