Notwithstanding their illegality, gravity knives are widely manufactured and sold across the country in hardware and outdoor stores under brand names such as Clip-it, Husky Utility Folding Knives and other brands. They are sold for and are used for purely legitimate purposes. Despite “locking” safety features, many can be “flicked” open with the appropriate amount of force. Thus, these knives are routinely carried by many New Yorkers for legitimate purposes ignorant of the fact that they may be in violation of the law and face a potential automatic one-year jail sentence.
New York court sets aside ?gravity knife? prosecution - The Washington Post