All TTI Impact Sockets and Accessories are crafted from Chrome Molybdenum Steel (Cr-Mo), specifically treated to withstand harsh conditions. They are engineered for use with both Pneumatic and Power Tools that demand greater torque and force. Note: Standard Chrome Vanadium Steel (Cr-V) are not to be used on Pneumatic or Power Tools. The TTI Impact Range are suited for tightening and loosening fasteners and are tested for durability. - Laser etched size markings for easy size reference - Colour coding rings for easy measurement system identification - Black phosphate finish for superior corrosion resistance - High Torque drive system transfers torque from corners to flay surface to avoid rounding fasteners - Constructed from Chrome Molybdenum last and withstand harsh conditions - Designed to be used with Power Tools and Pneumatic Tools - Manufactured in Taiwan