The Milwauke SHOCKWAVE Impact Duty™ Socket Extensions provide you with better access in hard to reach places and offers extreme impact durability in high torque applications. Milwaukee's laser-etched size markings allow for fast identification of drive size and length. The dual-hole design and ring groove allow you to easily attach and remove the extensions. All MILWAUKEE® SHOCKWAVE™ Impact Duty™ Socket Extensions are backed by Milwaukee Lifetime Guarantee and meet ASME industry standards.