California Code, Penal Code - PEN § 4502

(a) Every person who, while at or confined in any penal institution, while being conveyed to or from any penal institution, or while under the custody of officials, officers, or employees of any penal institution, possesses or carries upon his or her person or has under his or her custody or control any instrument or weapon of the kind commonly known as a blackjack, slungshot, billy, sandclub, sandbag, or metal knuckles, any explosive substance, or fixed ammunition, any dirk or dagger or sharp instrument, any pistol, revolver, or other firearm, or any tear gas or tear gas weapon, is guilty of a felony and shall be punished by imprisonment pursuant to subdivision (h) of Section 1170 for two, three, or four years, to be served consecutively.

(b) Every person who, while at or confined in any penal institution, while being conveyed to or from any penal institution, or while under the custody of officials, officers, or employees of any penal institution, manufactures or attempts to manufacture any instrument or weapon of the kind commonly known as a blackjack, slungshot, billy, sandclub, sandbag, or metal knuckles, any explosive substance, or fixed ammunition, any dirk or dagger or sharp instrument, any pistol, revolver, or other firearm, or any tear gas or tear gas weapon, is guilty of a felony and shall be punished by imprisonment pursuant to subdivision (h) of Section 1170 for 16 months, or two or three years, to be served consecutively.

(c) For purposes of this section, “penal institution” means the state prison, a prison road camp, prison forestry camp, or other prison camp or farm, or a county jail or county road camp.