3.02 The Bat
(a) The bat shall be a smooth, round stick not more than 2.61 inches in diameter at the thickest part and not more than 42 inches in length. The bat shall be one piece of solid wood.
(b) Cupped Bats. An indentation in the end of the bat up to 1 1/4 inches in depth is permitted and may be no wider than two inches and no less than one inch in diameter. The indentation must be curved with no foreign substance added.
(c) The bat handle, for not more than 18 inches from its end, may be covered or treated with any material or substance. Any such material or substance that extends past the 18-inch limitation shall cause the bat to be removed from the game.
(d) No colored bat may be used in a professional game unless approved by the Rules Committee.