California Code, Vehicle Code - VEH § 473

(a) A “pocket bike” is a two-wheeled motorized device that has a seat or saddle for the use of the rider, and that is not designed or manufactured for highway use. “Pocket bike” does not include an off-highway motorcycle, as defined in Section 436.

(b) For purposes of this section, a vehicle is designed for highway use if it meets the applicable Federal Motor Vehicle Safety Standards, as contained in Title 49 of the Code of Federal Regulations, and is equipped in accordance with the requirements of this code.