Cal. Pub. Cont. Code § 20473

Before the making of any contract the bidder shall give a bond to the district for the faithful performance of his contract, which shall be signed by the bidder and sureties satisfactory to the commission, in an amount equal to at least 50 percent of the amount of the contract price and shall give another bond conditioned upon the payment of claims for labor and material in connection with the performance of his contract containing the terms and conditions set forth in Chapter 3 of Division 5 of Title 1 of the Government Code and subject to the provisions of that chapter.