Official bat length < 34 inches and weight < 38 ounces, and < 2.25 inches in diameter. The official bat must bear either the ASA 2000 Certification Mark, ASA 2004 Certification Mark, or ASA 2013 Certification Mark, as shown below and must not be listed on the ASA Non-Approved Bat List with 2000 or 2004 Certification Mark.