Thats the thing, just cause you bought it legally doesn't mean its legal. If you got pulled over or stopped by police for some reason (even if you're not doing anything wrong) and they found it you could have been charged with possession of an offensive weapon under pa title 18 section 908. Why? Just cause it opened with a spring. Which is why the ACLU supported the bill, because prosecutors were unfairly charging people for having a knife that they used for work.