(a) No person shall carry on or about his person any weapon known or designated as a slingshot, slung shot, brass knuckles, billy, blackjack or other weapons of similar character. This section shall not apply to any such weapons when designated for use by officers of the law, nor to such officer while on duty.
(b) Whoever violates this section is guilty of a minor misdemeanor on a first offense; on each subsequent offense such person is guilty of a misdemeanor of the third degree.