Milwaukee 3/4" Drive 39mm Impact Socket - 49666377 The Milwaukee SHOCKWAVE Impact Duty Impact Sockets feature the boldest, longest-lasting markings and extreme impact durability in high torque applications. The stamped and ink-filled size markings make it easy to select the right socket every time throughout the life of the socket. Engineered with high strength forged steel for optimised performance in heavy-duty applications, and a non-slip hex geometry prevents fastener rounding. The dual-hole design and ring groove allow for easy socket attachment and removal. All SHOCKWAVE Impact Duty Sockets are backed by a Lifetime Guarantee and meet ASME industry standards.