Little League requires that a bat be no more than 33" in length and no more than 2 5/8" in diameter. All non-wood bats must have the words "USA Baseball" stamped on them.
Getting the right size bat will have a direct impact on your child's skills development and enjoyment of the game. We highly recommend NOT buying a bat that is too big, with the assumption that he/she will "grow into it."
For the Length, a good rule of thumb is to take your chld's age and add 20 to it (see chart). If your child is small for his/her age and/or less experienced, consider going down one inch. If your child is big for his/her age and/or more experienced, consider going up one inch.
For the Weight, most players use anywhere from "Drop 5" to "Drop 12." This means that the number of ounces the bat weighs is from 5 to 12 less than the number of inches the bat is long. So a 28" bat that weighs 16 oz. is considered a "Drop 12." A lighter bat will allow your child to swing the bat faster, while a heavier bat will provide more power.
Some divisions require a face cage on the helmet, while others do not. Below is a breakdown by division that lays out the requirements.
Tee Ball and Farm - Face cage highly recommended
A, AA, and AAA - Face cage required
Minors and Majors - Face cage optional