RULE 3. EQUIPMENT
THE OFFICIAL BAT. The bat shall be a smooth cylinder with a knob. Only bats that pass through a 2-1/4-inch (5.7150 cm) diameter bat ring are legal. Each bat shall be no more than 2-1/4 inches (5.7150 cm) in diameter at its thickest part, no more than 34 inches (86.360 cm) in length, and not exceed 38 ounces (1077.30 g) in weight. There shall be no devices, attachments, or wrappings that cause the handle to become flush with the knob. All bats shall meet the USA/ASA bat performance standard. Laser etching, other than on the barrel is permissible.
a. All bats must bear the USA/ASA approved certification mark and must not be listed on an USA/ASA Banned Bat list unless it bears the USA/ASA approved recertification mark; or
b. Must be included on a list of approved bat models published by USA/ASA; or
c. Must be in the sole opinion and discretion of the umpire, have been manufactured prior to 2000 and, if tested, would comply with the USA/ASA bat performance standards then in effect.
d. Safety grip or cork, tape (no smooth plastic tape) or composition material, may not exceed two layers of tape and must be a continuous spiral. Any resin or pine tar is permissible on this part of the bat. Tape must be at least 10 inches long and not more than 15 inches.
e. The bat’s knob may be solid or hollowed out to house an embedded metric sensor. If a sensor is used, it shall
(1) Not affect performance
(2) Be secured by a locking mechanism and a back-up mechanism to keep it in place.
(3) Have a distinguishing “off line” mode to prevent data from being accessed during a game.