No person may possess in any park any thing specifically designed for and presently capable of causing, or carried with the intent to threaten or cause, bodily harm to another. Things prohibited under this Section include, but are not limited to:  any firearm, pellet gun, spring-loaded weapon, stun gun or taser, any knife having a blade that projects or swings into position by force of a spring or by centrifugal force, any knife with a blade longer than 3-½ inches, any dirk, dagger, icepick, sling shot, slungshot, metal knuckles, nunchaku, studded handcoverings, swords, straight razors, tear gas containers, saps, sap gloves, hatchets or axes. The prohibitions of this Section do not apply to handguns lawfully carried by persons exempt from local regulation under ORS 166.173. The prohibitions of this Section do not apply to any thing possessed or used to carry out actions authorized by any contract or permit in any park.