This set includes nine of the most popular Torx sizes for automotive applications. The six smaller bits are 1/4" drive, and the three larger bits are 3/8" drive. The set includes T-10, T-15, T-20, T-25, T-27, T-30, T-40, T-45 and T-50 in a convenient holder. The T-47, T-55 and T-60 bits are available individually A part of the 37600 Super Torx set, which is 20 percent stronger than one-piece Torx bits. This is 9 out of 12, of the most popular Torx sizes for automotive applications.