Features a Special 'Lock Ball' Torx Socket for Cylinder Head Bolts. Fits Cylinder Head Bolts on M42 and M50 Engines. 1/2-Inch Square Drive with 6-Inch (15-Centimeter) Shaft. Heavy-Duty Construction Allows for Strength and Durability. Whether Tuning up Your ‘68 Corvette or Changing the Oil on a John Deere Tractor, CTA can Supply You with the Tools Needed to do the Job.