California Code, Vehicle Code - VEH § 28150

(a) No vehicle shall be equipped with any device that is designed for, or is capable of, jamming, scrambling, neutralizing, disabling, or otherwise interfering with radar, laser, or any other electronic device used by a law enforcement agency to measure the speed of moving objects.

(b) No person shall use, buy, possess, manufacture, sell, or otherwise distribute any device that is designed for jamming, scrambling, neutralizing, disabling, or otherwise interfering with radar, laser, or any other electronic device used by a law enforcement agency to measure the speed of moving objects.

(c) Except as provided in subdivision (d), a violation of subdivision (a) or (b) is an infraction.

(d) When a person possesses four or more devices in violation of subdivision (b), the person is guilty of a misdemeanor.

(e) Notwithstanding any other provision of law, a person who has a valid federal license for operating the devices described in this section may transport one or more of those devices if the license is carried in the vehicle transporting the device at all times when the device is being transported.