Section 17290.
Cal. Penal Code - PEN § 17290.
in effectAs used in this part, “undetectable knife” means any knife or other instrument, with or without a handguard, that satisfies all of the following requirements:
(a)
It is capable of ready use as a stabbing weapon that may inflict great bodily injury or death.
(b)
It is commercially manufactured to be used as a weapon.
(c)
It is not detectable by a metal detector or magnetometer, either handheld or otherwise, which is set at standard calibration.
Source: CA Legislative Counsel Bulk DataURL: https://downloads.leginfo.legislature.ca.gov/pubinfo_2025.zipFetched: 6/27/2026