Attached is the 2018 NEW approved baseball bat list. Look for the USA Baseball logo on the taper of a bat to know it is approved. Approved youth bats are 27” – 32” with barrel diameters up to 2 5/8”. Approved tee ball bats are 26” and shorter.
Approved Bat List: https://usabat.com/
About USABat: https://usabat.com/about/
Tee Ball Info: https://usabat.com/approved-tee-balls/