Rawlings 2014 RX4 SL5RX4 Baseball Bat (-5) This RX4 alloy barrel end construction for consistent performance 2 5/8 barrel diameter Approved by USSSA, Babe Ruth, Pony, AABC, Dixie, BPA, Dizzy Dean and other associations that allow 2 5/8 barrels with 1.15 BPF standard