California Code, Penal Code - PEN § 30401

(a) The department may, upon receipt of a written request or form prescribed by the department, issue a determination to a person regarding whether an item or kit is a firearm precursor part.

(b) Any request or form submitted pursuant to subdivision (a) shall be executed under the penalty of perjury with a complete and accurate description of the item or kit, the name and address of the manufacturer or importer thereof, and a sample of the item or kit for examination.

(c) The sample of the item or kit shall include all accessories and attachments relevant to the firearm precursor part determination as each determination is limited to the submitted sample. The sample shall include any associated templates, jigs, molds, equipment, or tools that are made available by the seller, distributor, or manufacturer of the item or kit to the purchaser or recipient of the item or kit, and any instructions, guides, or marketing materials if they will be made available by the seller, distributor, or manufacturer with the item or kit.

(d) Upon completion of the examination, the department may return the sample to the person who made the request unless a determination is made that return of the sample would be a, or would place the person in, violation of the law. Unless otherwise stated by the department, a determination made by the department pursuant to this section shall not be deemed by any person to be applicable to, or authoritative with respect to, any other sample, design, model, or configuration.