A box cutter with an exposed blade falls within those prohibited weapons listed in Penal Code section 626.10, subdivision (a), prohibiting specified weapons on school grounds. Appellant, a juvenile, was stopped and searched by a school employee who saw him jump over the schools perimeter fence. Inside appellants backpack, the employee discovered a razor blade knife with the blade exposed. Appellant testified he brought it to school to use as a weapon for his protection. Under the rules of statutory construction, the court found that the language of section 626.10, subdivision (a) which prohibits possession of a razor with an unguarded blade, encompassed a box cutter with an exposed blade. The court distinguished In re Michael R. (2004) 120 Cal.App.4th 1203, where the blade of the box cutter in question was retracted into its casing.