California Code, Penal Code - PEN § 20165

(a) Any person who, for commercial purposes, purchases, sells, manufactures, ships, transports, distributes, or receives, by mail order or in any other manner, an imitation firearm, except as authorized by this section, is liable for a civil fine in an action brought by the city attorney or the district attorney of not more than ten thousand dollars ($10,000) for each violation.

(b) The manufacture, purchase, sale, shipping, transport, distribution, or receipt, by mail or in any other manner, of an imitation firearm is authorized if the device is manufactured, purchased, sold, shipped, transported, distributed, or received for any of the following purposes: